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July 2000 PRELIMINARY
ML4835* Compact Fluorescent Electronic Dimming Ballast Controller
GENERAL DESCRIPTION
The ML4835 is a complete solution for a dimmable or a non-dimmable, high power factor, high efficiency electronic ballast especially tailored for a compact fluorescent lamp (CFL). The Bi-CMOS ML4835 contains controllers for "boost" type power factor correction as well as for a dimming ballast with end-of-lamp life detection. The PFC circuits uses a new , simple PFC topology which requires only one loop for compensation. In addition, this PFC can be used with either peak- or average-current mode. This system produces a power factor of better than 0.99 with low input current THD. The ballast controller section provides for programmable starting sequence with individual adjustable preheat and lamp out-of-socket interrupt times. The ML4835 provides a shut down for both PFC and ballast controllers in the event of end-of-life for the CFL.
FEATURES
s s s s s s s s s s
Power detect for end-of-lamp-life detection Low distortion , high efficiency continuous boost, peak or average current sensing PFC section Leading- and trailing-edge synchronization between PFC and ballast One to one frequency operation between PFC and ballast Programmable start scenario for rapid/instant start lamps Triple frequency control network for dimming or starting to handle various lamp sizes Programmable restart for lamp out condition to reduce ballast heating. Internal over-temperature shutdown PFC over-voltage comparator eliminates output "runaway" due to load removal Low start-up current; < 0.55mA
(* Indicates Part is End Of Life as of July 1, 2000)
BLOCK DIAGRAM
13 4 3 2 PVFB/OVP 1 RSET RT/CT RT2 CRAMP PIFBO PIFB PEAO POWER FACTOR CONTROLLER ANTI-FLASH COMPENSATION AND POWER DIMMING LEVEL INTERFACE CONTROL AND GATING LOGIC INTERRUPT 10 LAMP FB 5 LEAO 6
OUT A VARIABLE FREQUENCY OSCILLATOR THREE-FREQUENCY CONTROL SEQUENCER VCO PRE-HEAT AND INTERRUPT TIMERS END-OF-LAMP DETECT AND POWER SHUTOFF UNDER-VOLTAGE AND THERMAL SHUTDOWN AGND REF 14 20 VCC 19 LAMP OUT DETECT AND AUTOMATIC LAMP RESTART RX/CX 11 OUTPUT DRIVERS 17 OUT B 16 PFC OUT 18 PGND 15
7 9 8
PWDET 12
1
ML4835
PIN CONFIGURATION
ML4835 20-Pin SOIC (S20) 20-Pin DIP (P20)
PVFB/OVP PEAO PIFB PIFBO LAMP FB LEAO RSET RT2 RT/CT INTERRUPT 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 REF VCC PFC OUT OUT A OUT B PGND AGND CRAMP PWDET RX/CX
PIN DESCRIPTION
PIN NAME FUNCTION PIN NAME FUNCTION
1 2 3
PVFB/OVP PEAO PIFB
Inverting input to the PFC error amplifier and OVP comparator input. PFC error amplifier output and compensation node
10
INTERRUPT Input used for lamp-out detection and restart. A voltage less than 1V will reset the IC and cause a restart after a programmable interval. RX/CX PWDET CRAMP AGND PGND OUT B OUT A PFC OUT VCC REF Sets the timing for preheat and interrupt. Lamp output power detection Integrated voltage of the error amplifier out Analog ground Power ground. Ballast MOSFET driver output Ballast MOSFET driver output Power factor MOSFET driver output Positive supply voltage Buffered output for the 7.5V reference
11 Senses the inductor current and peak current sense point of the PFC cycle by cycle current limit Output of the current sense amplifier. Placing a capacitor to ground will average the inductor current. Inverting input of the lamp error amplifier, used to sense and regulate lamp arc current. Also the input node for dimmable control. Output of the lamp current error transconductance amplifier used for lamp current loop compensation External resistor which SETS oscillator FMAX, and RX/CX charging current Oscillator timing component to set start frequency Oscillator timing components 12 13 14 5 LAMP FB 15 16 17 18 19 20
4
PIFBO
6
LEAO
7 8 9
R SET RT2 RT/CT
2
ML4835
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. Supply Current (ICC) ............................................................. 65mA Output Current, Source or Sink (OUT A, OUT B, PFC OUT) DC ........................... 250mA PIFB Input Voltage ............................................-3V to 2V Maximum Forced Voltage (PEAO, LEAO) ............................................ -0.3V to 7.7V Maximum Forced Current (PEAO, LEAO) ...................................................... 20mA Junction Temperature .............................................. 150C Storage Temperature Range ...................... -65C to 150C Lead Temperature (Soldering, 10 sec) ..................... 260C Thermal Resistance (qJA) ML4835CP .......................................................... 65C/W ML4835CS .......................................................... 80C/W
OPERATING CONDITIONS
Temperature Range ....................................... 0C to 85C
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, VCC = VCCZ -0.5V, RSET = 11.8kW, RT = 15.4kW, RT2 = 67.5kW, CT = 1.5nF, TA = Operating Temperature Range (Note 1)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS LAMP CURRENT AMPLIFIER (LAMP FB, LEAO) Input Bias Current Small Signal Transconductance Input Bias Voltage Output Low Output High Source Current Sink Current LAMP FB = 3V, RL = LAMP FB = 2V, RL = LAMP FB = 0V, LEAO = 6V LAMP FB = 5V, LEAO = 0.3V 7.1 -80 80 35 -0.3 0.2 7.5 -220 220 -0.3 75 -1.0 105 5.0 0.4 A
V V V A A
PFC VOLTAGE FEEDBACK AMPLIFIER ( PEAO, PVFB/OVP) Input Bias Current Small Signal Transconductance Input Bias Voltage Output Low Output High Source Current Sink Current PFC CURRENT-LIMIT COMPARATOR (PIFB) Current-Limit Threshold Propagation Delay PFC OVP COMPARATOR OVP Threshold Hysteresis Propagation Delay 2.65 0.14 2.75 0.20 1.4 2.85 0.30 V V s 100mV Step and 100mV Overdrive -0.9 -1.0 100 -1.1 V ns PVFB = 3V, RL = PVFB = 2V, RL = PVFB = 0V, PEAO = 6V PVFB = 5V, PEAO = 0.3V 6.4 -80 80 35 -0.3 0.2 6.8 220 220 -0.3 75 -1.0 105 5.0 0.4 A
V V V A A
W W
3
ML4835
ELECTRICAL CHARACTERISTICS
SYMBOL OSCILLATOR Initial Accuracy (FMIN) Voltage Stability (FMIN) Temperature Stability (FMIN) Total Variation (FMIN) Initial Accuracy (START) Voltage Stability (START) Temparature Stability (START) Total Variation (START) Ramp Valley to Peak Initial Accuracy (Preheat) Total Variation (Preheat) CT Discharge Current Output Drive Deadtime REFERENCE BUFFER Output Voltage Line Regulation Load Regulation Temperature Stability Total Variation Long Term Stabilty Short Circuit Current RSET Voltage 2.4 Line, Load, Temperature Tj=125C, 1000 hrs 7.35 5 40 2.5 2.6 TA = 25C, IO = 0mA VCCZ - 4V < VCC < VCCZ - 0.5V 1mA < IO < 10mA 7.4 7.5 10 2 0.4 7.65 7.6 25 15 V mV mV % V mV mA V TA = 25C Line, Temperature VRTCT = 2.5V CT = 1.5nF 60.8 60.8 6.0 Line, Temperature 49 2.5 64 64 7.5 0.7 67.2 67.2 9.0 Line, Temperature TA = 25C 39.2 49 50 0.3 0.3 51 TA = 25C VCCZ - 4V < VCC < VCCZ - 0.5V 39.2 40 0.3 0.3 40.8 51 40.8 kHz % % kHz kHz % % kHz V kHz kHz mA us PARAMETER
(Continued)
CONDITIONS MIN TYP MAX UNITS
4
ML4835
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
(Continued)
CONDITIONS MIN TYP MAX UNITS
PREHEAT AND INTERRUPT TIMER (RX = 346kW, CX = 10F) Initial Preheat Period Subsequenct Preheat Period Interrupt Period RX/CX Charging Current RX/CX Open Circuit Voltage RX/CX Maximum Voltage Preheat Lower Threshold Preheat Upper Threshold Start Period End Threshold Interrupt Disable Threshold Hysteresis Input Bias Current POWER SHUTDOWN Power Shutdown Voltage OUTPUTS (OUT A, OUT B, PFC OUT) Output Voltage Low IOUT = 20mA IOUT = 200mA Output Voltage High Output Voltage High Output Voltage Low in UVLO Output Rise and Fall Time UNDER VOLTAGE LOCKOUT AND BIAS CIRCUITS IC Shunt Voltage (VCCZ) Start-up Threshold (VCC START) Hysteresis Start-up Current Interrupt Current Operating Current Shutdown Temperature Hysteresis
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions.
0.86 0.72 5.9 -50 0.4 7.0 1.6 4.4 6.2 1.1 0.16 -54 0.7 7.3 1.75 4.65 6.6 1.25 0.26 -58 1.0 7.8 1.9 4.9 6.9 1.4 0.36 1
s s s A V V V V V V V A
0.9
1
1.1
V
0.1 1.0 VCC-0.2 VCC-2.0 VCC-0.1 VCC-1.0
0.2 2.0
V V V V
IOUT = 20mA IOUT = 200mA IOUT = 10mA, VCC < VCC START CL=1000pF
0.2 50
V ns
ICC=15mA
14.0
14.8
15.5
V V V A A mA C C
VCCZ-1.5 VCCZ-1.0 VCCZ-0.5 3.0 VCC START -0.2V (VCC-0.5V), INTERRUPT = 0V (VCC-0.5V) 3.7 350 500 5.5 130 30 4.4 550 750 8.0
5
ML4835
FUNCTIONAL DESCRIPTION
The ML4835 consists of peak or average current controlled continuous boost power factor front end section with a flexible ballast control section. Start-up and lampout retry timing are controlled by the selection of external timing components, allowing for control of a wide variety of different lamp types. The ballast section controls the lamp power using frequency modulation (FM) with additional programmability provided to adjust the VCO frequency range. This allows for the IC to be used with a variety of different output networks. Figure 1 depicts a detailed block diagram of ML4835. The ML4835 provides several safety features. See the corresponding sections for more details: * End-of-lamp life detection to detect EOL and shut-off lamps; See End Of Life Section. * Thermal shutdown for temperature sensing extremes; See IC Bias, Under-Voltage Lockout and Thermal Shutdown Section. * Relamping starting with anti-flash for programmable restart for lamp out conditions while minimizing "flashing" when powering from full power to dimming levels; See Starting, Re-Start, Preheat and Interrupt Section
REF 20 19 14 VCC AGND REF 6.75V
+ -
REF_OK
THERMAL SHUTDOWN TEMP 130C/100C
OUT A 17
+ -
OUT B 16 PGND
-
Q UVLO Q
R PWDET S
+ -
15 12 1.0V
14V
+
13 1
CRAMP PREHEAT PVFB/OVP
- + +
COMP
V
TO
2.5V PEAO 2 PIFBO 4 PIFB 3 PFC OUT 18
+
I
4.75V/ 1.75V
Q Q
S R
1.25V/1V INTERRUPT 10
-
-
- + -
RX/CX 6.75V/1.25V
R S
Q Q CLK1
Q T Q /2
+
RT2
8
+
-1V 2.75V PVFB RX/CX
+ -
-
R ILIM S
Q Q PFC CONTROLLER CLK OSCILLATOR RT/CT 9
OVP
LEAO 6 LAMP FB
-
11 7
V TO I RSET
+
5 2.5V
V TO I
Figure 1. Detailed Block Diagram
6
ML4835
FUNCTIONAL DESCRIPTION
(Continued) POWER FACTOR SECTION The ML4835 power factor section is a peak or average current sensing boost mode PFC control circuit in which only voltage loop compensation is needed. It is simpler than a conventional average current control method. It consists of a voltage error amplifier, a current sense amplifier (no compensation is needed), an integrator, a comparator, and a logic control block. In the boost topology, power factor correction is achieved by sensing the output voltage and the current flowing through the current sense resistor. Duty cycle control is achieved by comparing the integrated voltage signal of the error amplifier and the voltage across RSENSE. The duty cycle control timing is shown in Figure 3. The ML4835 implements a triple frequency operation scheme: programmable three-frequency sequence for preheat, ignition, and dimming, that extends lamp life, simplifies lamp network design, and starts lamps at any dimming level without flashing. This addresses the need for a high-Q network for starting sequence and low-Q network for operation, minimizing parasitic losses and improving overall power efficiency. The values for the pre-heat, start, operation, and restart can be programmed or selected (Figure 2).
PREHEAT
SET TIME VALUES FOR PREHEAT, START AND OPERATION, AND RESTART
f1
ML4835
HIGH Q
LOW Q
f2
START
f3
OPERATION
Figure 2. Three Frequency Design Model
L
SW2 RA
VOUT LAMP INVERTER LAMP NETWORK
EMI FILTER RSENSE SW1 RB
LAMP
3 PIFB -A PIFBO
4 +
18
PFC OUT
1 PVFB/OVP R Q
- S PIFBO OSC RAMP V TO I + CLK CRAMP 13 CRAMP 2 R1 C2 C1 PEAO VREF1 CLK PEAO -
PFC OUT
Figure 3. ML4835 PFC Controller Section
7
ML4835
FUNCTIONAL DESCRIPTION
(Continued) OVERVOLTAGE PROTECTION AND INHIBIT The OVP pin serves to protect the power circuit from being subjected to excessive voltages if the load should change suddenly (lamp removal). A divider from the high voltage DC bus sets the OVP trip level. When the voltage on PVFB/OVP exceeds 2.75V, the PFC transistor are inhibited. The ballast section will continue to operate. TRANSCONDUCTANCE AMPLIFIERS
CRAMP PEAO MAX (1 - D)Ts - Dt = 22K
Setting minimum input voltage for output regulation can be achieved by selecting CRAMP as follows for peak current mode:
CRAMP = PEAO MAX (1 - D)Ts - Dt 22K
:
? !
V - 2VIN 2POUT - OUT (1 - D)Ts 8 R SENSE VIN 2L

1

"# $#
(1)
And for average current mode:
:
? !
V 2POUT - OUT (1 - D)Ts 8 R SENSE VIN 2L

1
"# $#
(1a)
Where Dt is the dead time.
The PFC voltage feedback amplifier is implemented as an operational transconductance amplifier. It is designed to have low small signal forward transconductance such that a large value of load resistor (R1) and a low value ceramic capacitor (<1F) can be used for AC coupling
CURRENT MIRROR
POWER DETECT
IN gmVIN 2
OUT
IQ + IQ - gmVIN 2
io = gmVIN
POWER LEVEL TRIP POINT
ML4835
POWER SHUTOFF
IN
OUT CURRENT MIRROR
Figure 4. Simplified Model of ML4835 EOL Functionality
Figure 6. Output Configuration
iO
PVFB/OVP 1 2.5V - + R1 C1 C2
0 VIN DIFFERENTIAL LINEAR SLOPE REGION
Figure 5. Compensation Network
Figure 7. Transconductance Amplifier Characteristics
8
ML4835
REF 20 DURING PREHEAT ICHG = 2.5V RSET AFTER PREHEAT LEA_ENB = HI ICHG = 5V - 7.5V RSET 8K25% LEA_ENB = LOW ICHG = 5V - LEAO RSET 8K25%
+
RT2
RT
ICHG
8
RT2
9 LEA_ENB
+
RT/CT 3.75/1.25V
-
INTERRUPT 10 1.25/1.0V VCC 0.625 RSET RX/CX
- +
CT
5.5mA
19
7.5V
NOTE 1: RSET SHOULD BE SELECTED SUCH THAT AFTER PREHEAT WITH LEA_ENB "HI", ICHG MUST BE < 0. ICHG IS A UNI-DIRECTIONAL SOURCE CURRENT ONLY.
11
- +
4.75/1.25V
CLOCK
tDIS VTH = 3.75V
tCHG
CT VTL = 1.25V
Figure 8. Oscillator Block Diagram and Timing
VCC VCCZ V(ON) V(OFF)
ICC 5.5mA
t
0.34mA t
Figure 9. Typical VCC and ICC Waveforms when the ML4835 is Started with a Bleed Resistor from the Rectified AC Line and Bootstrapped from an Auxiliary Winding.
9
ML4835
FUNCTIONAL DESCRIPTION
(Continued) OSCILLATOR The VCO frequency ranges are controlled by the output of the LFB amplifier (RSET). As lamp current decreases, LFB OUT falls in voltage, causing the CT charging current to increase, thereby causing the oscillator frequency to increase. Since the ballast output network attenuates high frequencies, the power to the lamp will be decreased. The oscillator frequency is determined by the following equations: FOSC = and
t CHG = R T C T In
(C1) in the frequency compensation network. The compensation network shown in Figure 5 will introduce a zero and a pole at: fZ = 1 2p R 1C1 fP = 1 2p R 1C 2 (2)
Figure 4 shows the output configuration for the operational transconductance amplifiers. A DC path to ground or VCC at the output of the transconductance amplifiers will introduce an offset error. The magnitude of the offset voltage that will appear at the input is given by VOS = io/gm. For an io of 1A and a gm of 0.05 W the input referred offset will be 20mV. Capacitor C1 as shown in Figure 5 is used to block the DC current to minimize the adverse effect of offsets. Slew rate enhancement is incorporated into all of the operational transconductance amplifiers in the ML4835. This improves the recovery of the circuit in response to power up and transient conditions. The response to large signals will be somewhat non-linear as the transconductance amplifiers change from their low to high transconductance mode, as illustrated in Figure 7. END OF LAMP LIFE At the end of a lamp's life when the emissive material is depleted, the arc current is rectified and high voltage occurs across the lamp near the depleted cathode. The ballast acts as a constant current source so power is dissipated near the depleted cathode which can lead to arcing and bulb cracking. Compact fluorescent lamps are more prone to cracking or shattering because their small diameter can't dissipate as much heat as the larger linear lamps. Compact fluorescents also present more of a safety hazard since they are usually used in downlighting systems without reflector covers. EOL and the ML4835
1 t CHG + t DIS
(3)
V V
REF
REF
+ ICHG R T - VTL + IICHG R T - VTH

(4)
The oscillator's minimum frequency is set when ICHG = 0 where: FMIN @ 1 0.51 R T C T (5)
The oscillator's start frequency can be expressed by: FSTART = 0.51 R T R T 2 C T
2
1
7
(5a)
Both equations assume that tCHG >> tDIS. When LFB OUT is high, ICHG = 0 and the minimum frequency occurs. The charging current varies according to two control inputs to the oscillator: 1. The output of the preheat timer 2. The voltage at LFB OUT (lamp feedback amplifier output) In preheat condition, charging current is fixed at
The ML4835 uses a circuit that creates a DC voltage representative of the power supplied to the lamps through the inverter. This voltage is used by the ML4835 to latch off the ballast when it exceeds an internal threshold. An external resistor can be used as the "EOL latch resistor" to set the power level trip point, as shown in by R9 in Figure 12. See Micro Linear ML4835 User Guide and applications notes for more details. Figure 4 illustrates a simplified model of ML4835 EOL functionality. BALLAST OUTPUT SECTION The IC controls output power to the lamps via frequency modulation with non-overlapping conduction. This means that both ballast output drivers will be low during the discharging time tDIS of the oscillator capacitor CT.
ICHG (PREHEAT ) =
25 . R SET
(6)
In running mode, charging current decreases as the voltage rises from 0V to VOH at the LAMP FB amplifier. The charging current behavior can be expressed as: ICHG = 5V LEAO R SET 8k 25% (7)
The highest frequency is attained when ICHG is highest, which is attained when voltage at LFB OUT is at 0V: ICHG(0) = 5 R SET (8)
10
ML4835
FUNCTIONAL DESCRIPTION
(Continued) The circuit in Figure 10 controls the lamp starting scenarios: Filament preheat and lamp out interrupt. CX is charged with a current of IR(SET)/4 and discharged through RX. The voltage at CX is initialized to 0.7V (VBE) at power up. The time for CX to rise to 4.75V is the filament preheat time. During that time, the oscillator charging current (ICHG) is 2.5/RSET. This will produce a high frequency for filament preheat, but will not produce sufficient voltage to ignite the lamp or cause significant glow current. After cathode heating, the inverter frequency drops to FSTART causing a high voltage to appear to ignite the lamp. If lamp current is not detected when the lamp is supposed to have ignited, the CX charging current is shut off and the inverter is inhibited until CX is discharged by RX to the 1.25V threshold. Shutting off the inverter in this manner prevents the inverter from generating excessive heat when the lamp fails to strike or is out of socket. Typically this time is set to be fairly long by choosing a large value of RX. LFB OUT is ignored by the oscillator until INTERRUPT is above 1.25V The CX pin is clamped to about 7.5V. Care should also be taken not to turn on the VCCZ clamp so as not to dissipate excessive power in the IC. This will cause the temp sensor to become active at a lower ambient temperature. A summary of the operating frequencies in the various operating modes is shown below. OPERATING MODE Preheat After Preheat Dimming Control OPERATING FREQUENCY [F(MAX) to F(MIN)] 2 F(START) F(MIN) to F(MAX) Highest lamp power, and lowest output frequency are attained when voltage at LFB OUT is at its maximum output voltage (VOH). In this condition, the minimum operating frequency of the ballast is set per equation 5 above. For the IC to be used effectively in dimming ballasts with higher Q output networks a larger CT value and lower RT value can be used, to yield a smaller frequency excursion over the control range (voltage at LFB OUT). The discharge current is set to 5.5mA. Assuming that IDIS >>IRT:
t DIS( VCO) @ 600 C T
IC BIAS, UNDER-VOLTAGE LOCKOUT AND THERMAL SHUTDOWN
(9)
The IC includes a shunt clamp which will limit the voltage at VCC to 15V (VCCZ). The IC should be fed with a current limited source, typically derived from the ballast transformer auxiliary winding. When VCC is below VCCZ - 1.1V, the IC draws less than 0.55mA of quiescent current and the outputs are off. This allows the IC to start using a "bleed resistor" from the rectified AC line. To help reduce ballast cost, the ML4835 includes a temperature sensor which will inhibit ballast operation if the IC's junction temperature exceeds 130C. In order to use this sensor in lieu of an external sensor, care should be taken when placing the IC to ensure that it is sensing temperature at the physically appropriate point in the ballast. The ML4835's die temperature can be estimated with the following equation:
TJ @ TA + (PD + 65 C / W)
(10)
STARTING, RE-START, PREHEAT AND INTERRUPT The lamp starting scenario implemented in the ML4835 is designed to maximize lamp life and minimize ballast heating during lamp out conditions.
0.625 RSET RX/CX 10 RX CX 1.25/4.75
+ -
HEAT
INTERRUPT 9 1.0/1.25
+ -
LEA_ENB OR DIMMING LOCKOUT
S
+
Q
INHIBIT
1.25/6.75
-
R
Figure 10. Lamp Preheat and Interrupt Timers
11
ML4835
TYPICAL APPLICATIONS
The ML4835 can be used for a variety of lamp types: T4 or compact fluorescent lamps IEC T8 (linear lamps) T5 linear lamps T12 linear lamps The ML4835 can also be used for dimming applications. For example, 20:1 dimming can be achieved using the ML4835 with external dimming units. The applications schematics shown in Figures 12, 13, and 14 are examples of the various uses of the ML4835.
7.5 6.75 RX/CX 4.75 1.25 .7 0
HEAT LEA_ENB OR DIMMING LOCKOUT
INTERRUPT
INHIBIT
Figure11. Lamp Starting and Restart Timing
12
ML4835
HOT
F1
L1 C1 3.3nF C2 3.3nF
R4, 62k D1-D4: 1A, 600V C3 0.15F D8, 1A, 600V D3 D1
6 10 8
120VRMS L2 NEUTRAL
T1 D4 D2
9
D10, 0.1A 75V D5 1A, 50V R1 0.33 R2 100 D6 1A, 50V C5 0.1F C6 0.1F
D7 1A, 600V (ULTRAFAST) D9, 0.1A 75V C7 100F D14 0.1A 75V R3 820
D11, 15V, 0.5W
D16, 0.1A, 75V R6 432k R25 100
3
Q1 4.5A, 500V
C8 47F
6
2
R11 150 Q2 2.5A, 500V
T3 C12 0.33F
4 3
C30 120pF C28 120pF
R R Y Y B B
D18 0.1A 75V
R7 432k
D17, 0.1A, 75V
7
6
2 1 9 8
1
R19, 16.2k R21, 51.1k
R8 5.76k R9 4.3 C9 1F R10 30
8
R12 150 Q3 2.5A, 500V
D19 1A 600V D15 1A 600V
7
C11 6800pF C14 0.015F
5 6
1
T3
10
U1 1 2 C29 100pF R15, 681k 3 4 5 6 7 C16 82nF C17 8.2nF C4 33nF C18 1.5nF R26 5k 8 R17 4.3k C20 1.5nF C22 1.5F 9 10 PVFB PEAO PIFB PIFBO LFB LEAO RSET RT2 RT/CT INTRPT
ML4835 REF VCC PFC OUT OUT A OUT B P GND A GND RAMP PW DET RX/CX R23, 200k C24 470pF 20 19 18 17 16 15 14 13 12 11
R24 20k
D12 0.1A, 75V
C15 1F
R14 22.6k
R13 1k C26 47F
R18 8.06k
C25 0.22F
C19 1F
R22 360k
C21 15F
C27 0.22F
C23 6.8F
R16 10k
D13 5.6V, 0.5W
DIMMER INTERFACE ASSEMBLY R5 1M Q1
3 4
D1 0.1A, 75V T1 C1 100F
R8 180
R6 3.32k
R3 16.2k R4 220k
3 2
8
+ - + -
4
U2A
1
R2 1.5k
1
R1 604
5
5 6
U2B
7
2 4
C4 D2 18V 10F R7 3.32k D3 C2 220pF
U1 C5 0.01F VIOLET GREY
C3, 1nF
MANUAL DIMMER 0-10VDC
Figure12. Ballast for Architectural Dimming Applications
13
ML4835
HOT
F1
L1 C1 3.3nF C2 3.3nF
R4, 62k D1-D4: 1A, 600V C3 0.15F D8, 1A, 600V D3 D1
6 10 8
120VRMS L2 NEUTRAL
T1 D4 D2
9
D7 1A, 600V (ULTRAFAST) D9, 0.1A 75V C7 100F D14 0.1A 75V R3 820
D11, 15V, 0.5W
D16, 0.1A, 75V R6 432k R25 100
3
D10, 0.1A 75V D5 1A, 50V R1 0.33 R2 100 D6 1A, 50V C5 0.1F C6 0.1F
Q1 4.5A, 500V
C8 47F
6
2
R11 150 Q2 2.5A, 500V
L3 D19 1A 600V
C12 0.33F
C13 2700pF T3
4 3
C30 120pF C28 120pF
R R Y Y B B
D18 0.1A 75V
R7 432k
D17, 0.1A, 75V
7
C11 6800pF
6 8
6 7
2 1 9 8
1
R19, 16.2k R21, 51.1k
R8 5.76k R9 4.3 C9 1F R10 30
8
R12 150 Q3 2.5A, 500V
D15 1A 600V
10
C14 0.015F
C10 0.33F
5 6
1
T3
10
U1 1 2 C29 100pF R15, 681k 3 4 5 6 7 C16 82nF C17 8.2nF C4 33nF C18 1.5nF R26 5k 8 R17 4.3k C20 1.5nF C22 1.5F 9 10 PVFB PEAO PIFB PIFBO LFB LEAO RSET RT2 RT/CT INTRPT
ML4835 REF VCC PFC OUT OUT A OUT B P GND A GND RAMP PW DET RX/CX R23, 200k C24 470pF 20 19 18 17 16 15 14 13 12 11
R24 20k
D12 0.1A, 75V
C15 1F
R14 22.6k
R13 1k C26 47F
R18 8.06k
C25 0.22F
C19 1F
R22 360k
C21 15F
C27 0.22F
C23 6.8F
R16 10k
D13 5.6V, 0.5W
DIMMER INTERFACE ASSEMBLY R5 1M Q1
3 4
D1 0.1A, 75V T1 C1 100F
R8 180
R6 3.32k
R3 16.2k R4 220k
3 2
8
+ - + -
4
U2A
1
R2 1.5k
1
R1 604
5
5 6
U2B
7
2 4
C4 D2 18V 10F R7 3.32k D3 C2 220pF
U1 C5 0.01F VIOLET GREY
C3, 1nF
MANUAL DIMMER 0-10VDC
Figure13. Ballast for Architectural Downlighting Applications
14
ML4835
HOT
F1
L1 C1 3.3nF C2 3.3nF
R4, 62k D1-D4: 1A, 600V C3 0.15F D8, 1A, 600V D3 D1
6 10 8
120VRMS L2 NEUTRAL
T1 D4 D2
9
D7 1A, 600V R6 432k D9, 0.1A 75V C7 100F D14 0.1A 75V R3 820
D11, 15V, 0.5W
D16, 0.1A, 75V
D10, 0.1A 75V D5 1A, 50V R1 0.33 R2 100 D6 1A, 50V C5 0.1F C6 0.1F
Q1 4.5A, 500V
R25 100
3
C8 47F
6
2
R11 150 Q2 2.5A, 500V
T3 C12 0.33F
4 3
C30 120pF C28 120pF
R R Y Y B B
D18 0.1A 75V
R7 432k
D17, 0.1A, 75V
7
6
2 1 9 8
1
R19, 16.2k R21, 51.1k
R8 5.76k R9 4.3 C9 1F R10 30
8
R12 150 Q3 2.5A, 500V
D19 1A 600V D15 1A 600V
7
C11 6800pF C14 0.015F
5 6
1
T3
10
U1 1 2 C29 100pF R15, 681k 3 4 5 6 7 C16 82nF C17 8.2nF C4 33nF C18 1.5nF 8 R26 5k 9 10 R18 8.06k C20 1.5nF C22 1.5F PVFB PEAO PIFB PIFBO LFB LEAO RSET RT2 RT/CT INTRPT
ML4835 REF VCC PFC OUT OUT A OUT B P GND A GND RAMP PW DET RX/CX R23, 200k C24 470pF 20 19 18 17 16 15 14 13 12 11
R24 20k
D12 0.1A, 75V C26 47F
C25 0.22F
R22 360k
C21 15F
C27 0.22F
C23 6.8F
R13 1k
Figure14. Non-Dimming Ballast for Downlighting Applications
15
ML4835
PHYSICAL DIMENSIONS
inches (millimeters)
Package: S20 20-Pin SOIC
0.498 - 0.512 (12.65 - 13.00) 20
0.291 - 0.301 0.398 - 0.412 (7.39 - 7.65) (10.11 - 10.47) PIN 1 ID
1 0.024 - 0.034 (0.61 - 0.86) (4 PLACES) 0.050 BSC (1.27 BSC) 0.095 - 0.107 (2.41 - 2.72) 0 - 8
0.090 - 0.094 (2.28 - 2.39)
0.012 - 0.020 (0.30 - 0.51)
SEATING PLANE
0.005 - 0.013 (0.13 - 0.33)
0.022 - 0.042 (0.56 - 1.07)
0.007 - 0.015 (0.18 - 0.38)
Package: P20 20-Pin PDIP
1.010 - 1.035 (25.65 - 26.29) 20
PIN 1 ID
0.240 - 0.260 0.295 - 0.325 (6.09 - 6.61) (7.49 - 8.26)
0.060 MIN (1.52 MIN) (4 PLACES)
1 0.055 - 0.065 (1.40 - 1.65) 0.100 BSC (2.54 BSC) 0.015 MIN (0.38 MIN)
0.170 MAX (4.32 MAX)
0.125 MIN (3.18 MIN)
0.016 - 0.022 (0.40 - 0.56)
SEATING PLANE
0 - 15
0.008 - 0.012 (0.20 - 0.31)
16
ML4835
PHYSICAL DIMENSIONS
inches (millimeters)
ORDERING INFORMATION
PART NUMBER ML4835CP (End Of Life) ML4835CS (End Of Life) TEMPERATURE RANGE 0C to 70C 0C to 70C PACKAGE 20-Pin DIP (P20) 20-Pin SOIC (S20)
(c) Micro Linear 1999.
is a registered trademark of Micro Linear Corporation. All other trademarks are the property of their respective owners.
DS4835-03 2092 Concourse Drive San Jose, CA 95131 Tel: (408) 433-5200 Fax: (408) 432-0295 www.microlinear.com
Products described herein may be covered by one or more of the following U.S. patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376; 5,652,479; 5,661,427; 5,663,874; 5,672,959; 5,689,167; 5,714,897; 5,717,798; 5,742,151; 5,747,977; 5,754,012; 5,757,174; 5,767,653; 5,777,514; 5,793,168; 5,798,635; 5,804,950; 5,808,455; 5,811,999; 5,818,207; 5,818,669; 5,825,165; 5,825,223; 5,838,723; 5.844,378; 5,844,941. Japan: 2,598,946; 2,619,299; 2,704,176; 2,821,714. Other patents are pending. Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design. Micro Linear does not assume any liability arising out of the application or use of any product described herein, neither does it convey any license under its patent right nor the rights of others. The circuits contained in this data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility or liability for use of any application herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application.
17

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