View SC194BMLTRT_4123398.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Selectable 3.6V/3.3V/3.0V/2.5V 1A Synchronous Buck Converter
POWER MANAGEMENT Description
The SC194B is a synchronous step-down converter with integrated power devices. Four selectable output voltages suitable for portable device interface, memory function blocks, and 5V to 3.3V voltage conversion are available. Automatic selection of Power Save Mode (PSAVE) is supported which enhances efficiency. A 100% duty cycle mode allows operation for input voltages close to the required output voltage. The need for external components is minimized by providing internal feedback compensation, and allowing selection of the required output voltage by hard wiring VID code inputs. The maximum current rating of the internal MOSFET switches allows a DC output current of 1A. The switching frequency is nominally set to 1MHz, allowing the use of small inductors and capacitors. A flexible clocking scheme is used that allows synchronization to an external oscillator or control by the internal oscillator. The device can operate in either forced PWM mode or in PSAVE mode. If PSAVE mode is enabled the part will automatically enter PSAVE at light loads to maintain maximum efficiency across the full load range. For noise sensitive applications, PSAVE mode can be disabled by synchronizing to an external oscillator, or pulling the SYNC/ PWM pin high. Shutdown turns off all the control circuitry to achieve a typical shutdown current of 0.1A.
SC194B
Features
Up to 95% efficiency PSAVE operation to maximize efficiency Output current -- 1A Input range -- 2.7V to 5.5V Four selectable output voltages Quiescent current -- 17A in PSAVE Dynamic voltage positioning capability Fixed 1MHz frequency or 750kHz to 1.25MHz synchronized operation Current mode operation for excellent line and load transient response 100% duty cycle in dropout Soft-start Over-temperature and short-circuit protection Lead-free package -- 3mm x 3mm MLPD
Applications
PDA Pocket PC and Smart Phones USB Powered Modems CPUs and DSPs PC Cards and Notebooks xDSL Applications Standard 5-V to 3.3-V Conversion
Typical Application Circuit
SC194B
VIN 3.6V to 5.5V CIN 10F VIN EN SYNC/PWM VID0 VID1 MODE LX VOUT PGND GND
L1 4.7H COUT 22F
VOUT 3.3V 1A
August 24, 2006
1
www.semtech.com
SC194B
POWER MANAGEMENT Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not recommended.
Parameter Input Supply Voltage Logic Inputs (SYNC/PWM, EN, MODE, VID0, VID1) Output Voltage LX Voltage Thermal Impedance Junction to Ambient(1) VOUT Short-Circuit to GND Operating Ambient Temperature Range Storage Temperature Junction Temperature Peak IR Reflow Temperature ESD Protection Level (2)
Symbol VIN VN VOUT VLX JA tSC TA TS TJC TP VESD
Maximum -0.3 to 7 -0.3 to VIN +0.3, 7V Max -0.3 to VIN +0.3, 7V Max -1 to VIN +1, 7V Max 40 Continuous -40 to +85 -60 to +160 -40 to +150 260 2
Units V V V V C/W s C C C C kV
Note: (1) Calculated from package in still air, mounted to 3" x 4.5", 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. (2) Tested according to JEDEC standard JESD22-A114-B.
Electrical Characteristics
Unless otherwise noted: VIN = 5V ,VOUT = 3.3V, EN = VIN, SYNC/PWM = VIN, MODE = VIN , TA = -40 to 85C. Typical values are at TA =25C.
Parameter Input Voltage Range VOUT Accuracy VOUT Temperature Accuracy Line Regulation Load Regulation (PWM) PSAVE Regulation P-Channel On Resistance N-Channel On Resistance Start-Up Time P-Channel Current Limit
(c) 2006 Semtech Corp.
Symbol VIN VOUT VOUT(T) VOUT LINE VOUT LOAD VOUT PSAVE RDSP RDSN TSTART ILIM(P)
Conditions VIN > VOUT + dropout IOUT = 0.5A, TA = 25C VOUT = 2.5/3.0/3.3/3.6V IOUT = 0.5A, TA=-40C to 85C VIN = 2.7V to 5.5V, VOUT = 2.5V, IOUT = 0.5A, TA=-40C to 85C IOUT = 0A to 1A SYNC/PWM = GND, COUT=22F ILX = 100mA, VIN=3.6V ILX = 100mA, VIN=3.6V
Min 2.7
Typ
Max 5.5 1
Units V % % % % %
0.3 0.4 0.3 +1.3 -0.3 0.275 0.165
0.7 0.65 0.65 +1.6 -0.6
5 VIN = 2.7V to 5.5V
2
ms A
1.33
1.9
2.47
www.semtech.com
SC194B
POWER MANAGEMENT Electrical Characteristics (Cont.)
Parameter Quiescent Current Shutdown Current LX Leakage Current PMOS LX Leakage Current NMOS Oscillator Frequency SYNC Frequency (upper) SYNC Frequency (lower) UVLO Threshold (upper) UVLO Hysteresis Thermal Shutdown Thermal Shutdown Hysteresis Logic Input High Logic Input Low Logic Input Current High Logic Input Current Low Symbol IQ ISD ILXP ILXN fOSC fSYNCU fSYNCL VUVL VUVLHYS TSD TSD-HYS VIH VIL IIH IIL EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE -2 -2 0.1 0.1 1.6 0.6 2 2 Conditions SYNC/PWM = GND, IOUT = 0A, VOUT = 1.04 x VOUT(Programmed), VIN= 3.6V EN = GND, LX = OPEN, VIN= 3.6V VIN = 3.6V, LX = GND, EN = GND VIN = 3.6V, LX = 3.6V, EN = GND VIN= 3.6V VIN= 3.6V VIN= 3.6V 2.38 2.52 100 145 10 -2 0.85 1.25 750 2.65 Min Typ 17 0.1 0.1 0.1 1.0 1.15 Max 28 1 2 Units A A A A MHz MHz kHz V mV C C V V A A
(c) 2006 Semtech Corp.
3
www.semtech.com
SC194B
POWER MANAGEMENT Pin Configuration Ordering Information
DEVICE
SC194BMLTRT(1)(2)
PACKAGE
MLP 3x3-10 Evaluation Board
VIN MODE SYNC/PWM EN VOUT
1 2 3 4
T
10
LX PGND GND VID1 VID0
TOP VIEW
9 8 7 6
Notes: 1) Lead-free packaging only. This product is fully WEEE and RoHS compliant. 2) Available in tape and reel only. A reel contains 3000 devices.
Ordering Information
SC194BEVB
5
Programmable Output Voltage
VID1 VID0 0 1 0 1 SC194B VOUT 2.5V 3.0V 3.3V 3.6V
MLP10: 3X3 10 LEAD
0 0 1 1
Marking Information
194B yyww xxxx
yy = two digit year of manufacture ww = two digit week of manufacture xxxx = lot number
(c) 2006 Semtech Corp.
4
www.semtech.com
SC194B
POWER MANAGEMENT Pin Descriptions
Pin # 1 2 Pin Name VIN MODE Pin Function Input power supply voltage MODE select pin where MODE = VIN to select 100% duty cycle function and MODE = GND to disable Oscillator synchronization input -- Tie to VIN for forced PWM mode or GND to allow the part to enter PSAVE mode at light loads. Apply an external clock signal for frequency synchronization. Enable digital input -- A high input enables the SC194B, a low disables and reduces quiescent current to less than 1A. In shutdown, LX becomes high impedance. Regulated output voltage and feedback for SC194B Logic level bit 0 is used in conjunction with VID1 to set the output voltage. Connect high or low as required to select the desired output voltage. If not connected, the output voltage will be indeterminate. Logic level bit 1 is used in conjunction with VID0 to set the output voltage. Connect high or low as required to select the desired output voltage. If not connected, the output voltage will be indeterminate. Ground Power Ground Inductor connection to the switching FETs Pad is for heatsinking purposes -- not connected internally. Connect exposed pad to ground plane using multiple vias.
3
SYNC/PWM
4 5 6
EN VOUT VID0
7 8 9 10 T
VID1 GND PGND LX THERMAL PAD
(c) 2006 Semtech Corp.
5
www.semtech.com
SC194B
POWER MANAGEMENT Block Diagram
Plimit Amp 1 Current Amp VIN
EN
4
SYNC/ PWM
3
OSC & Slope Generator Control Logic
PWM Comp 10 LX
500mV Ref Error Amp MODE 2 PSAVE Comp
Nlimit Amp 9 PGND
VID1 VID0
7 6
Voltage Select
8
GND
VOUT
5
(c) 2006 Semtech Corp.
6
www.semtech.com
SC194B
POWER MANAGEMENT Applications Information
SC194B Detailed Description The SC194B is a synchronous step-down Pulse Width Modulated (PWM), DC-DC converter utilizing a 1MHz fixed-frequency current mode architecture. The device is designed to operate in fixed-frequency PWM mode across the full load range and can enter power save mode (PSAVE) utilizing Pulse Frequency Modulation (PFM) at light loads to maximize efficiency. Operation During normal operation the PMOS MOSFET is activated on each rising edge of the internal oscillator. Current feedback for the switching regulator is through the PMOS current path, and it is amplified and summed with the internal slope compensation network. The voltage feedback loop uses an internal feedback divider. The ontime is determined by comparing the summed current feedback and the output of the error amplifier. The period is set by the onboard oscillator or by an external clock attached to the SYNC/PWM pin. The SC194B has an internal synchronous NMOS rectifier and does not require a Schottky diode on the LX pin. Programmable Output Voltage The SC194B has four pre-determined output voltage values which can be individually selected by the correct programming of the VID0 and VID1 pins (see Programmable Output Voltage table on Page 4). This eliminates the need for external programming resistors saving PCB area and inventory. The VID pins can be statically tied to GND or VIN for fixed output configurations or they may be driven by a microprocessor enabling the possibility of dynamic voltage adjustment for host equipment "sleep" states. Oscillator Synchronization Opotions The SC194B is designed to operate in continuous conduction, fixed-frequency mode. When the SYNC/PWM pin is tied high the part runs in PWM mode using the internal oscillator. The part can be synchronized to an external clock by driving a clock signal into the SYNC/ PWM pin. The part synchronizes to the rising edge of the clock. Protection Features The SC194B provides the following protection features: * Thermal shutdown * Current limit
(c) 2006 Semtech Corp. 7
* Over-voltage protection * Soft-start Thermal Shutdown The device has a thermal shutdown feature to protect the SC194B if the junction temperature exceeds 145C. In thermal shutdown the on-chip power devices are disabled, tri-stating the LX output. Switching will resume when the temperature drops by 10C. During this time if the output voltage decreases by more than 60% of its programmed value, a soft-start will be invoked. Current Limit The PMOS and NMOS power devices of the buck switcher stage are protected by current limit functions. In the case of a short to ground on the output, the part enters frequency foldback mode that causes the switching frequency to divide by a factor determined by the output voltage. This prevents the inductor current from "stair-casing". Over-Voltage Protection Over-voltage protection is provided on the SC194B. In the event of an over-voltage on the output in switcher mode, the PWM drive is disabled, tri-stating the LX output. The part will not resume switching until the output voltage has fallen below 2% of the regulation voltage. Soft-Start The soft-start mode is enabled after every shutdown cycle to limit in-rush current. In conjunction with the frequency foldback, this controls the maximum current during startup. The PMOS current limit is stepped up through seven soft-start levels to the full value by a timer driven from the internal oscillator. During soft-start, the switching frequency is stepped by 1/8, 1/4, and 1/2 of the internal oscillator frequency up to the full value, under control of three output voltage thresholds. As soon as the output voltage is within 2% of the regulation voltage, soft-start mode is disabled. Power Save Mode Operation The PSAVE mode may be selected by tying the SYNC/PWM pin to GND. Selecting PSAVE mode will enable the SC194B to automatically activate/deactivate operation at light loads maximizing efficiency across the full load range. The SC194B automatically detects the load current at which it should enter PSAVE mode. The SC194B is optimized to track maximum efficiency with respect to VIN.
www.semtech.com
SC194B
POWER MANAGEMENT Applications Information (Cont.)
In PSAVE mode VOUT is driven from a lower level to an upper level by a switching burst. Once the upper level has been reached the switching is stopped and the quiescent current is reduced. VOUT falls from the upper to lower levels in this low current state as the load current discharges the output capacitor. The burst-to-off period in PSAVE will decrease as the load current reduces. The PSAVE switching burst frequency is controlled so that the inductor current ripple is similar to that in PWM mode. The SC194B automatically detects when to exit PSAVE mode by monitoring VOUT. For the SC194B to exit PSAVE mode, the load must be increased, causing VOUT to decrease until the power save exit threshold is reached. PSAVE levels are set high to minimize the undershoot when exiting PSAVE. The lower PSAVE comparator level is set +0.7% above VOUT, and the upper comparator level at +1.5% above VOUT, with the exit threshold at -2% below VOUT. If PSAVE operation is required then a 22F output capacitor must be used. Power Save Operation
BURST OFF Higher Load Applied
100% Duty Cycle Operation The 100% duty cycle mode may be selected by connecting the MODE pin high. This will allow the SC194B to maintain output regulation under low input voltage/high output voltage conditions. In 100% duty cycle operation, as the input supply drops toward the output voltage, the PMOS on-time increases linearly above the maximum value in fixed-frequency operation until the PMOS is active continuously. Once the PMOS is switched on continuously, the output voltage tracks the input voltage minus the voltage drop across the PMOS power device and inductor according to the following relationship:
VOUT
where, VOUT VIN IOUT RDSP RIND
VIN IOUT (RDSP RIND )
= Output voltage = Input voltage = Output current = PMOS switch ON resistance = Series resistance of the inductor
1.5% 0.7%
PSAVE Mode at Light Load VOUT PWM Mode at Medium/ High Load
Inductor Selection The SC194B is designed for use with a 4.7H inductor. The magnitude of the inductor current ripple is dependent on the inductor value and can be determined by the following equation:
IL
-2%
VOUT VOUT 1 L fosc VIN
Inductor Current
This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple current. The inductor should have a low DCR to minimize the conduction losses and maximize efficiency. As a minimum requirement, the DC current rating of the inductor should be equal to the maximum load current plus half of the inductor current ripple as shown by the following equation:
0A
Time
IL(PK)
(c) 2006 Semtech Corp. 8
IOUT(MAX)
IL 2
www.semtech.com
SC194B
POWER MANAGEMENT Applications Information (Cont.)
Final inductor selection will depend on various design considerations such as efficiency, EMI, size and cost. Table 1 lists the manufacturers of practical inductor options. Table 1 -- Recommended Inductors
Manufacturer/Part No. BI Technologies HM66304R7 Coilcraft D01608C-472ML TDK VLCF4018T- 4R7N1R0-2 Value (H) 4.7 DCR () 0.072 Saturation Current (A) 1.32 Tolerance (+%) Dimensions LxWxH (mm) 4.7 x 4.7 x3.0
Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their low ESR and superior temperature and voltage characteristics. Y5V capacitors should not be used as their temperature coefficients make them unsuitable for this application. Table 2 lists the manufacturers of recommended capacitor options. Table 2 -- Recommended Capacitors
Manufacturer/Part No. Murata GRM21BR60J226ME39L Murata GRM188R60J106MKE19 TDK C2012X5R0J106K Value (F) 22 Rated Voltage (VDC) 6.3 Temperature Characteristic X5R Case Size
20
4.7
0.09
1.5
20
6.6 x 4.5 x3.0
0805
4.7
0.101
1.07
30
4.3 x 4.0 x1.8
10
6.3
X5R
0603
10
6.3
X5R
0603
CIN Selection The source input current to a buck converter is noncontinuous. To prevent large input voltage ripple a low ESR ceramic capacitor is required. A minimum value of 10F should be used for sufficient input voltage filtering and a 22F should be used for improved input voltage filtering. COUT Selection The internal compensation is designed to work with a certain output filter corner frequency defined by the equation:
fC 1 2 L COUT
Note: Where PSAVE operation is required 22F must be used for COUT.
This single pole filter is designed to operate with a minimum output capacitor value of 10F. Larger output capacitor values will improve transient performance. If PSAVE operation is required the minimum capacitor value is 22F. Output voltage ripple is a combination of the voltage ripple from the inductor current charging and discharging the output capacitor and the voltage created from the inductor current ripple through the output capacitor ESR. Selecting an output capacitor with a low ESR will reduce the output voltage ripple component, as can be seen in the following equation:
VOUT(ESR) IL(ripple) ESR COUT
(c) 2006 Semtech Corp.
9
www.semtech.com
SC194B
POWER MANAGEMENT Applications Information (Cont.)
PCB Layout Considerations Poor layout can degrade the performance of the DC-DC converter and can contribute to EMI problems, ground bounce and resistive voltage losses. Poor regulation and instability can result. A few simple design rules can be implemented to ensure good layout: 1. Place the inductor and filter capacitors as close to the device as possible and use short wide traces between the power components. 2. Route the output voltage feedback path away from the inductor and LX node to minimize noise and magnetic interference. 3. Maximize ground metal on the component side to improve the return connection and thermal dissipation. Separation between the LX node and GND should be maintained to avoid coupling of switching noise to the ground plane. 4. Use a ground plane with several vias connecting to the component side ground to further reduce noise interference on sensitive circuit nodes.
GND
VIN
CIN
LX
SC194B
LOUT
COUT
VOUT
GND
(c) 2006 Semtech Corp.
10
www.semtech.com
SC194B
POWER MANAGEMENT Typical Characteristics
Efficiency vs. Load Current VOUT = 3.6V
100 90 80 70
VIN=4.2V, PSAVE VIN=5.0V, PSAVE VIN=3.9V, PSAVE
Efficiency vs. Load Current VOUT = 3.3V
100 90 80 70
Efficiency (%)
VIN=4.2V, PSAVE VIN=5.0V, PSAVE VIN=3.9V, PSAVE
Efficiency (%)
60 50 40 30 20 10 0 0.0001
VIN=3.9V, PWM VIN=5.0V, PWM
60 50
VIN=3.9V, PWM
40 30
VIN=5.0V, PWM
VIN=4.2V, PWM
20 10
0.001 0.01 IOUT (A) 0.1 1 10
VIN=4.2V, PWM
0 0.0001
0.001
0.01 IOUT (A)
0.1
1
10
Efficiency vs. Load Current VOUT = 3.0V
100 90 80 70
VIN=4.2V, PSAVE VIN=5.0V, PSAVE VIN=5.0V, PWM VIN=3.6V, PSAVE
Efficiency vs. Load Current VOUT = 2.5V
100 90 80 70
Efficiency (%)
VIN=5.0V, PSAVE VIN=4.2V, PSAVE VIN=3.3V, PSAVE
Efficiency (%)
60 50 40
VIN=3.6V, PWM
60 50 40 30
VIN=4.2V, PWM VIN=3.3V, PWM VIN=5.0V, PWM
30
VIN=4.2V, PWM
20 10 0 0.0001 0.001 0.01 IOUT (A) 0.1 1 10
20 10 0 0.0001 0.001 0.01 IOUT (A) 0.1 1 10
Efficiency vs. Input Voltage VOUT = 3.3V
100
VOUT=3.3V,PSAVE VOUT=3.3V,PWM
PWM to PSAVE Hysteresis
95
PSAVE Entry IOUT Decreasing
95
94
90
VOUT=2.5V,PWM
Efficiency (%)
93
PSAVE EXIT IOUT Increasing
Eff (%)
VOUT=2.5V,PSAVE
85
92
80
PWM Mode
75
91
70 2.5
3
3.5
4 Vin (V)
4.5
5
5.5
6
90 0.1
0.15
0.2
0.25
0.3 IOUT (A)
0.35
0.4
0.45
0.5
IOUT=500 mA(PWM)/50 mA(PSAVE)
(c) 2006 Semtech Corp.
11
www.semtech.com
SC194B
POWER MANAGEMENT Typical Characteristics
VOUT vs. VIN
3.6 3.4 3.2 3
VOUT=3.3V,PSAVE
Load Regulation
3.292 3.29 3.288 3.286 3.284 3.282 3.28 3.278 0
Vin=5V, Vout=3.3V,PWM
VOUT=3.3V,PWM
VOUT (V)
2.8 2.6 2.4 2.2 2 2.5
VOUT=2.5V,PSAVE
VOUT=2.5V,PWM
3
3.5
4 VIN (V)
4.5
5
VOUT (V)
5.5
6
0.2
0.4
0.6
0.8 IOUT (A)
1
1.2
1.4
1.6
IOUT=500 mA(PWM)/50 mA(PSAVE)
VOUT vs. Temperature
3.35 3.34 3.33 3.32
VOUT = 3.3V
Quiescent Current vs. Input Voltage
22 21 20
TA=85C PSAVE Mode
VIN=5.0V,PSAVE
Quiescent Current (uA)
19 18 17 16 15 14 13
TA=-40C TA=25C
VOUT (V)
3.31 3.3 3.29 3.28 3.27 -50 -40 -30 -20 -10
VIN=5.0V,PWM
0
10
20 TA (C)
30
40
50
60
70
80
90
12 2.5
3
3.5
4 VIN(V)
4.5
5
5.5
6
Quiescent Current vs. Input Voltage
6
PWM Mode
N-Channel RDSON vs. Input Voltage
0.22
TA=-40C
5.5
TA=85C
0.20
TA=85C
Quiescent Current (mA)
5
0.18
RDSON ()
TA=25C
TA=25C
4.5
0.16
TA=-40C
4
0.14
3.5
0.12
3 2.5
3
3.5
4 VIN (V)
4.5
5
5.5
6
0.10 2.7
3.2
3.7
4.2 VIN (V)
4.7
5.2
(c) 2006 Semtech Corp.
12
www.semtech.com
SC194B
POWER MANAGEMENT Typical Characteristics (Cont.)
P-Channel RDSON vs. Input Voltage
0.40
1050 1040
Switching Frequency vs. Temperature
0.35
Switching Frequency (kHz)
1030
VIN=5.5V
0.30
1020 1010
VIN=2.7V
RDSON ()
TA=85C
0.25
TA=25C
1000 990
VIN=3.6V
0.20
TA=-40C
980 970 960
0.15
0.10 2.7
3.2
3.7
4.2 VIN(V)
4.7
5.2
950 -50
-30
-10
10
30
50
70
90
110
130
TJ (C)
100% Duty Cycle Mode
PSAVE Operation
VOUT (50mV/div) ILX (200mA/div)
VOUT (50mV/div)
ILX (500mA/div)
VLX (2V/div) Time (400ns/div) Condition VIN= 3.8V, lOUT= 1A, VOUT= 3.3V Time (2s/div) Condition VIN=5V, lOUT=50mA, VOUT=3.3V
VLX (5V/div)
PWM Operation
PSAVE Start-UP
VEN (2V/div) VOUT (20mV/div) VOUT (2V/div) ILX (500mA/div)
VLX (5V/div) Time (1s/div) Condition VIN=5V, lOUT=50mA, VOUT=3.3V Time (400s/div) Condition VIN=5V, lOUT=10mA, VOUT=3.3V
IIN (200mA/div)
(c) 2006 Semtech Corp.
13
www.semtech.com
SC194B
POWER MANAGEMENT Typical Characteristics (Cont.)
PWM Start-Up Load Transient Response PWM
VEN (2V/div) VOUT (2V/div)
VOUT (200mV/div)
IOUT (500mA/div) IIN (200mA/div) Time (400s/div) Condition VIN= 5V, lOUT = 10mA, VOUT= 3.3V Time (400s/div) Condition VIN= 5V, lOUT = 1A to 100mA, VOUT = 3.3V
Load Transient Response PSAVE
VID Code Change PWM
VOUT (200mV/div)
VOUT (200mV/div)
IOUT (500VmA/div))
VVID1 (2V/div)
Time (400s/div) Condition VIN= 5V, lOUT = 1A to 100mA, VOUT = 3.3V
Time (400s/div) Condition VIN= 5V, lOUT = 1A, VOUT = 2.5 to 3.3V
(c) 2006 Semtech Corp.
14
www.semtech.com
SC194B
POWER MANAGEMENT Applications Circuits
VOUT = 3.6V Forced PWM and 100% Duty Cycle
SC194B VIN 3.9 to 5.5V CIN 10F VIN EN SYNC/PWM VID0 VID1 MODE LX VOUT PGND GND
L1 4.7H COUT 10F
VOUT 3.6V 1A
Dynamic Voltage Positioning for Reduced System Dissipation in "Sleep" Modes
VIN 2.7V to 5.5V CIN 10F SC194B VIN EN SYNC/PWM VID0 VID1 MODE LX 4.7H VOUT PGND GND COUT 22F L1 VOUT 3.3V norm VOUT 2.5V "sleep"
From uP Sleep controller
VOUT = 2.5V with PSAVE and 100% Duty Cycle
VIN 2.7V to 5.5V CIN 10F
SC194B VIN LX EN SYNC/PWM VOUT VID0 VID1 PGND MODE GND
L1 4.7H COUT 22F
VOUT 2.5V 1A
(c) 2006 Semtech Corp.
15
www.semtech.com
SC194B
POWER MANAGEMENT Outline Drawing - MLP-10
A
E
B
DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX
A A1 A2 b C D E e L N aaa bbb .031 .000 .007 .074 .042 .114 .039 .002 (.008) .009 .011 .079 .083 .048 .052 .118 .122 .020 BSC .012 .016 .020 10 .003 .004 0.80 1.00 0.00 0.05 (0.20) 0.18 0.23 0.30 1.87 2.02 2.12 1.06 1.21 1.31 2.90 3.00 3.10 0.50 BSC 0.30 0.40 0.50 10 0.08 0.10
E PIN 1 INDICATOR (LASER MARK)
A aaa C C 1 LxN 2 A1 A2 C
SEATING PLANE
D
N e bxN bbb CAB
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS.
(c) 2006 Semtech Corp.
16
www.semtech.com
SC194B
POWER MANAGEMENT Land Pattern - MLP-10
K
DIMENSIONS
DIM
C G H K P X Y Z
INCHES
(.112) .075 .055 .087 .020 .012 .037 .150
MILLIMETERS
(2.85) 1.90 1.40 2.20 0.50 0.30 0.95 3.80
(C)
H
G
Z
Y X P
NOTES: 1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.
Contact Information
Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804
www.semtech.com
(c) 2006 Semtech Corp. 17 www.semtech.com

▲Up To Search▲

Price & Availability of SC194BMLTRT

	To Download SC194BMLTRT Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .