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19-3554; Rev 1; 3/05
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
General Description
The MAX6977 serial-interfaced LED driver provides eight open-drain, constant-current sinking LED driver outputs rated at 5.5V. The MAX6977 operates from a 3V to 5.5V supply. The MAX6977 supply and the LEDs' supply may power up in any order. The constant-current outputs are programmed together to up to 55mA using a single external resistor. The MAX6977 operates with a 25Mb, industry-standard, 4-wire serial interface. The MAX6977 includes circuitry that automatically detects open-circuit LEDs. Fault status is loaded into the serial interface shift register when LE goes high, and is automatically shifted out on DOUT when the next data transmission is shifted in. The MAX6977 uses the industry-standard shift-registerplus-latch-type serial interface. The driver accepts data shifted into an 8-bit shift register using data input DIN and clock input CLK. Input data appears at the output DOUT eight clock cycles later to allow cascading of multiple MAX6977s. The latch-enable input LE loads the 8 bits of shift register data into an 8-bit output latch to set which LEDs are on and which are off. The outputenable input OE gates all eight outputs on and off, and is fast enough to be used as a PWM input for LED intensity control. For safety-related applications requiring a watchdog timer, refer to the MAX6978 data sheet that includes a fail-safe feature that blanks the display if the serial interface becomes inactive for more than 1s. The MAX6977 is one of a family of 12 shift-register-pluslatch-type LED drivers. The family includes 8-port and 16-port types, with 5.5V- or 36V-rated LED outputs, with and without open-circuit LED detection and watchdog. All versions operate from a 3V to 5.5V supply, and are specified over the -40C to +125C temperature range. 3V to 5.5V Logic Supply 8 Constant-Current LED Outputs Rated at 5.5V Up to 55mA Continuous Current per Output Output Current Programmed by Single Resistor 3% Current Matching Between Outputs 6% Current Matching Between ICs Reports Open-Circuit LED Faults -40C to +125C Temperature Range
Features
25Mb Industry-Standard 4-Wire Serial Interface at 5V
MAX6977
Ordering Information
PART MAX6977AUE MAX6977APE TEMP RANGE -40C to +125C -40C to +125C PIN-PACKAGE 16 TSSOP-EP* 16 PDIP 16 SSOP
MAX6977AEE -40C to +125C *EP = Exposed pad.
Typical Application Circuit and Selector Guide appear at end of data sheet.
Pin Configuration
TOP VIEW
Applications
Variable Message Signs Marquee Displays Point-of-Order Signs Traffic Signs Gaming Features Architectural Lighting
GND 1 DIN 2 CLK 3 LE 4 OUT0 5 OUT1 6 OUT2 7 OUT3 8
16 V+ 15 SET 14 DOUT
MAX6977AUE MAX6977APE MAX6977AEE
13 OE 12 OUT7 11 OUT6 10 OUT5 9 OUT4
TSSOP/PDIP/SSOP
________________________________________________________________ Maxim Integrated Products
1
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8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
ABSOLUTE MAXIMUM RATINGS
Voltage (with respect to GND) V+ ............................................................................-0.3V to +6V OUT_ .......................................................................-0.3V to +6V DIN, CLK, LE, OE, SET ................................-0.3V to (V+ + 0.3V) DOUT Current ..................................................................10mA OUT_ Sink Current .............................................................60mA Total GND Current ...........................................................480mA Continuous Power Dissipation (TA = +70C) 16-Pin SSOP (derate 7.1mW/C above +70C) ............571mW 16-Pin PDIP (derate 10.5mW/C above +70C)............842mW 16-Pin TSSOP (derate 21.3mW/C above +70C) ......1702mW Operating Temperature Range .........................-40C to +125C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, V+ = 3V to 5.5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = 5V, TA = +25C.) (Note 1)
PARAMETER Operating Supply Voltage Output Voltage Standby Current (Interface Idle, All Output Ports High Impedance, RSET = 360) Standby Current (Interface Running, All Output Ports High Impedance, RSET = 360) Supply Current (Interface Idle, All Output Ports Active Low, RSET = 360) Input High Voltage DIN, CLK, LE, OE Input Low Voltage DIN, CLK, LE, OE Hysteresis Voltage DIN, CLK, LE, OE Input Leakage Current DIN, CLK, LE, OE Output High-Voltage DOUT Output Low Voltage Output Current OUT_ Output Leakage Current OUT_ Watchdog Timeout SYMBOL V+ VOUT I+ All logic inputs at V+ or GND, DOUT unloaded 4.5 CONDITIONS MIN 3 TYP MAX 5.5 5.5 5.6 UNITS V V mA
I+
fCLK = 5MHz, OE = V+, DIN and LE = V+ or GND, DOUT unloaded
4.7
6
mA
I+
All logic inputs at V+ or GND, DOUT unloaded 0.7 V+
10
25
mA
VIH VIL VI IIH, IIL VOH VOL IOUT ILEAK tWD ISOURCE = 4mA ISINK = 4mA V+ = 4.5V to 5.5V, VOUT = 0.8V to 2.5V, RSET = 360 OE = V+, VOUT = V+
V 0.3 V+ 0.8 V V +1 A V 0.5 V mA A s
-1 V+ - 0.5V
42
50
56 1
1
2
_______________________________________________________________________________________
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
5V TIMING CHARACTERISTICS
(Typical Operating Circuit, V+ = 4.5V to 5.5V, TA = TMIN to TMAX, unless otherwise noted.) (Note 1)
PARAMETER CLK Clock Period CLK Pulse Width High CLK Pulse Width Low DIN Setup Time DIN Hold Time DOUT Propagation Delay DOUT Rise and Fall Time LE Pulse Width High LE Pulse Width (Fault-Detection Data Valid) LE Setup Time LE Rising to OUT_ Rising Delay LE Rising to OUT_ Falling Delay CLK Rising to OUT_ Rising Delay CLK Rising to OUT_ Falling Delay OE Rising to OUT_ Rising Delay OE Falling to OUT_ Falling Delay LED Output OUT_ Turn-On Fall Time LED Output OUT_ Turn-Off Rise Time SYMBOL tCP tCH tCL tDS tDH tDO tDR, tDF tLW tLF tLS tLRR tLRF tCRR tCRF tOEH tOEL tf tr 80% to 20% 20% to 80% (Note 2) (Note 2) (Note 2) (Note 2) CDOUT = 10pF, 20% to 80% 20 20 10 100 280 100 310 100 300 200 120 CONDITIONS MIN 40 19 19 4 8 12 32 10 TYP MAX UNITS ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns
MAX6977
_______________________________________________________________________________________
3
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
3.3V TIMING CHARACTERISTICS
(Typical Operating Circuit, V+ = 3V to 5.5V, TA = TMIN to TMAX, unless otherwise noted.) (Note 1)
PARAMETER CLK Clock Period CLK Pulse Width High CLK Pulse Width Low DIN Setup Time DIN Hold Time DOUT Propagation Delay DOUT Rise and Fall Time LE Pulse Width High LE Pulse Width (Fault-Detection Data Valid) LE Setup Time LE Rising to OUT_ Rising Delay LE Rising to OUT_ Falling Delay CLK Rising to OUT_ Rising Delay CLK Rising to OUT_ Falling Delay OE Rising to OUT_ Rising Delay OE Falling to OUT_ Falling Delay LED Output OUT_ Turn-On Fall Time LED Output OUT_ Turn-Off Rise Time tOEH tOEL tf tr 80% to 20% 20% to 80% tLW tLW tLS SYMBOL tCP tCH tCL tDS tDH tDO CDOUT = 10pF, 20% to 80% 20 20 15 100 310 100 330 100 330 200 120 CONDITIONS MIN 52 24 24 4 8 12 48 10 TYP MAX UNITS ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns
Note 1: All parameters tested at TA = +25C. Specifications over temperature are guaranteed by design. Note 2: See Figure 3.
Typical Operating Characteristics
(TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE (INTERFACE IDLE, ALL OUTPUTS OFF, RSET = 720)
MAX6977 toc01
SUPPLY CURRENT vs. SUPPLY VOLTAGE (INTERFACE IDLE, ALL OUTPUTS OFF, RSET = 360)
MAX6977 toc02
3.2 SUPPLY CURRENT (mA) 3.1 3.0 2.9 2.8 2.7 2.6 2.5 3.0
4.9 4.8 SUPPLY CURRENT (mA) 4.7 4.6 4.5 4.4 4.3 4.2 TA = -40C TA = +25C TA = +125C TA = +85C
TA = +125C
TA = +85C
12 SUPPLY CURRENT (mA)
TA = +125C
TA = +85C
9
TA = -40C
6 TA = -40C 3
TA = +25C
TA = +25C 3.5 4.0 4.5 5.0 5.5
4.1 4.0 3.0 3.5 4.0 4.5 5.0 5.5 0 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
MAX6977 toc03
3.3
5.0
SUPPLY CURRENT vs. SUPPLY VOLTAGE (INTERFACE IDLE, ALL OUTPUTS ON, RSET = 720)
15
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
Typical Operating Characteristics (continued)
(TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE (INTERFACE IDLE, ALL OUTPUTS ON, RSET = 360)
TA = +125C 12 SUPPLY CURRENT (mA) TA = +85C
MAX6977 toc04
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE (RSET = 720, V+ = 3.3V)
MAX6977 toc05
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE (RSET = 360, V+ = 3.3V)
MAX6977 toc06
15
30 25 20 15 10 5 0
60 50 PORT OUTPUT CURRENT (mA) 40 30 20 10 0
PORT OUTPUT CURRENT (mA)
TA = -40C TA = +25C TA = +85C TA = +125C
TA = -40C TA = +25C TA = +85C TA = +125C
9 TA = +25C
6
TA = -40C
3
0 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V)
0
0.5
1.0
1.5
2.0
2.5
3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE (RSET = 720, V+ = 5.0V)
MAX6977 toc07
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE (RSET = 360, V+ = 5.0V)
MAX6977 toc08
PORT OUTPUT CURRENT vs. SUPPLY VOLTAGE (RSET = 720, VOUT = 2V)
TA = +85C
MAX6977 toc09
30 25 20 15 10 5 0 0 0.5 1.0 1.5 2.0 2.5
60 50 PORT OUTPUT CURRENT (mA) 40 30 20 10 0
26.0 TA = +125C
PORT OUTPUT CURRENT (mA)
PORT OUTPUT CURRENT (mA)
TA = -40C TA = +25C TA = +85C TA = +125C
TA = -40C TA = +25C TA = +85C TA = +125C
25.5
25.0 TA = -40C 24.5
TA = +25C
24.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.0 3.5 4.0 4.5 5.0 5.5 PORT OUTPUT VOLTAGE (V) SUPPLY VOLTAGE (V)
3.0
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT vs. SUPPLY VOLTAGE (RSET = 360, VOUT = 2V)
MAX6977 toc10
PORT OUTPUT CURRENT vs. SET RESISTANCE
MAX6977 toc11
52 TA = +85C
50
PORT OUTPUT CURRENT (mA)
51
PORT OUTPUT CURRENT (mA)
TA = +125C
40
30
50 TA = -40C 49 TA = +25C
20
10
48 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V)
0 0 500 1000 1500 2000 2500 SET RESISTANCE ()
_______________________________________________________________________________________
5
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
Pin Description
PIN 1 2 3 4 5-12 13 14 15 16 PAD NAME GND DIN CLK LE OUT0-OUT7 OE DOUT SET V+ Exposed pad* Ground Serial-Data Input. Data is loaded into the internal 8-bit shift register on CLK's rising edge. Serial-Clock Input. Data is loaded into the internal 8-bit shift register on CLK's rising edge. Load-Enable Input. Data is loaded transparently from the internal shift register to the output latch while LE is high. Data is latched into the output latch on LE's falling edge, and retained while LE is low. LED Driver Outputs. OUT0-OUT7 are open-drain, constant-current sinking outputs rated to 5.5V. Output Enable Input. High forces outputs OUT0-OUT7 to high impedance, without altering the contents of the output latches. Low enables outputs OUT0-OUT7 to follow the state of the output latches. Serial-Data Output. Data is clocked out of the 8-bit internal shift register to DOUT on CLK's rising edge. LED Current Setting. Connect SET to GND through a resistor (RSET) to set the maximum LED current. Positive Supply Voltage. Bypass V+ to GND with a 0.1F ceramic capacitor. Exposed pad on package underside. Connect to GND. FUNCTION
*TSSOP package only.
CLK MAX6977
DIN
D0
SERIAL-TO-PARALLEL SHIFT REGISTER
D7
DOUT
LE
D0
LATCHES
D7
POWER-ON RESET
V+
OE V+
D0
CONSTANT-CURRENT SINKS
D7
CURRENT REFERENCE
FAULT DETECTION
RSET
GND OUT0 OUT1 OUT2 OUT5 OUT6 OUT7 GND
Figure 1. MAX6977 Block Diagram
Detailed Description
The MAX6977 LED driver comprises a 4-wire serial interface driving eight constant-current sinking opendrain output ports. The outputs drive LEDs in either static or multiplex applications (Figure 1). The constantcurrent outputs are guaranteed for current accuracy
6
not only with chip-supply voltage variations (5V 10% and 3V to 5.5V), but also over a realistic range of driver output voltage drop (0.5V to 2.5V). The drivers use current-sensing feedback circuitry (not simple current mirrors) to ensure very small current variations over the full allowed range of output voltage (see Typical Operating Characteristics).
_______________________________________________________________________________________
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
The 4-wire serial interface comprises an 8-bit shift register and an 8-bit transparent latch. The shift register is written through a clock input CLK and a data input DIN and the data propagates to a data output DOUT. The data output allows multiple drivers to be cascaded and operated together. The contents of the 8-bit shift register are loaded into the transparent latch through a latch-enable input LE. The latch is transparent to the shift register outputs when high, and latches the current state on the falling edge of LE. Each driver output is an open-drain constant-current sink that should be connected to the cathode of either a single LED or a series string of multiple LEDs. The LED anode can be connected to a supply voltage of up to 5.5V, independent of the MAX6977 supply, V+. The constant-current capability is up to 55mA per output, set for all eight outputs by an external resistor, RSET. pled on the rising edge of CLK (Table 1). Data is shifted in MSB first. This means that data bit D7 is clocked in first, followed by 7 more data bits finishing with the LSB D0. CLK is the serial clock input, which shifts data at DIN into the MAX6977 8-bit shift register on its rising edge. LE is the load input of the MAX6977 latch, which transfers data from the MAX6977 8-bit shift register to its 8bit latch when LE is a high (transparent latch), and latches the data on the LE falling edge of LE (Figure 2). The rising edge of LE loads fault data into the MAX6977 8-bit shift register, replacing bits D6 and D5 with fault data. This fault data is automatically shifted out through DOUT when the next display data is shifted in. The fourth input provides output enable control of the output drivers. OE is high to force outputs OUT0 to OUT7 high impedance, without altering the contents of the output latches, and low to enable outputs OUT0 to OUT7 to follow the state of the output latches. OE is independent of the operation of the serial interface. Data can be shifted into the serial interface shift register and latched regardless of the state of OE. DOUT is the serial-data output, which shifts data out from the MAX6977's 8-bit shift register on the rising edge of CLK. Data at DIN is propagated through the shift register and appears at DOUT eight clock cycles later.
MAX6977
Initial Power-Up and Operation
An internal reset circuit clears the internal registers of the MAX6977 on power-up. All outputs OUT0 to OUT7, therefore, initialize high impedance, and the interface output DOUT initializes low, regardless of the initial logic levels of the CLK, DIN, OE, and LE inputs.
4-Wire Serial Interface
The serial interface on the MAX6977 is a 4-wire serial interface using four inputs (DIN, CLK, LE, OE) and a data output (DOUT). This interface is used to write display data to the MAX6977. The serial interface data word length is 8 bits, D0-D7. The functions of the five interface pins follow. DIN is the serial-data input, and must be stable when it is sam-
LED Fault Detection
The MAX6977 includes circuitry that detects open-circuit LEDs automatically. An open-circuit fault occurs when an output is programmed to sink current but less than about 50% of the programmed current flows.
Table 1. 4-Wire Serial Interface Truth Table
SERIAL CLOCK DATA INPUT INPUT D0 CLK DIN H L X -- -- -- -- -- -- H L R0 X P1 -- SHIFT REGISTER CONTENTS D1 R1 R1 R1 X P2 -- D2 R2 R2 R2 X P3 -- ... Dn-1 Dn ... Rn-2 Rn-1 ... Rn-2 Rn-1 ... Rn-1 Rn ... -- X -- X -- ... Pn-1 Pn LOAD INPUT LE -- -- -- H L -- D0 -- -- -- R0 P0 X LATCH CONTENTS D1 -- -- -- R1 P1 X D2 -- -- -- R2 P2 X ... Dn-1 Dn -- -- -- -- -- -- -- -- -- BLANKING INPUT OE -- -- -- -- L H D0 -- -- -- -- P0 OUTPUT CONTENTS D1 -- -- -- -- P1 D2 -- -- -- -- P2 ... Dn-1 Dn -- -- -- -- -- -- -- -- -- -- -- --
-- Rn-1 Rn ... Pn-1 Pn ... X X
... Pn-1 Pn
Hi-Z Hi-Z Hi-Z ... Hi-Z Hi-Z
L = Low-logic level H = High-logic level X = Don't care P = Present state R = Previous state _______________________________________________________________________________________ 7
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
LE tCL tCH tCP CLK tDH tDS DIN D7 D6 D1 tDO DOUT D7 D0 tLS tLW tLF
OE tOEL
tOEW
tOEH 80% . tr 20% tf
OUT_
Figure 2. 4-Wire Serial Interface Timing Diagram
LE tLRF OUT_
LE tLRR OUT_
CLK tCRF OUT_
CLK tCRR OUT_
Figure 3. LE and CLK to OUT_ Timing
8
_______________________________________________________________________________________
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
Open circuits are checked just after the rising edge of LE, when new LED data is loaded into the output latches from the shift register(s). If one or more output port is detected with an open-circuit fault, then the 2 bits, D6 and D5, in the serial interface shift register are both set high. If no open-circuit faults are detected, then D6 and D5 are both cleared low. The data in other 6-bit positions in the serial interface shift register is not altered. Fault status is automatically shifted out on DOUT when the next data transmission is shifted in. LE is normally taken high after all 8 bits of new LED data have been clocked into the shift register, and so at that time, DOUT is outputting data bit D7. On the next two rising edges of CLK, the 2 fault status bits, D6 and D5, are clocked out in that order, followed by the remaining 5 unchanged data bits D4 to D0. A typical fault-detecting application tests all the shiftedout data. Bits D0-D4 and D7 are checked against the originally transmitted data to check data link integrity. Bits D5 and D6 are checked first to see that they contain the same data (validating the status), and second whether faults are reported by the actual logic level. The fault status bit identifies which driver chip has at least one open-circuit LED. It is possible to determine how many LEDs driven by a chip are at fault by running eight test patterns, each of which lights a different single LED. The fault status bit then effectively identifies only one output at a time. DUTY = PWM duty cycle applied to OE N = number of MAX6977 outputs driving LEDs at the same time (maximum is 8) VOUT = MAX6977 port output voltage when driving load LED(s) IOUT = LED drive current programmed by RSET PD = power dissipation, in mW if currents are in mA Dissipation example: IOUT = 47mA, N = 8, DUTY = 1, VOUT = 2V, V+ = 5.25V PD = (5.25V x 25mA) + (2V x 1 x 47mA x 8) = 0.883W Thus, for a 16-pin TSSOP package (TJA = 1 / 0.0213 = +46.95C/W from Absolute Maximum Ratings), the maximum allowed ambient temperature TA is given by: TJ(MAX) = TA + (PD x TJA) = +150C = TA + (0.883 x 46.95C/W) so TA = +108.5C.
MAX6977
Overtemperature Cutoff
The MAX6977 contains an internal temperature sensor that turns off all outputs when the die temperature exceeds approximately +165C. The outputs are enabled again when the die temperature drops below approximately +140C. Register contents are not affected, so when a driver is overdissipating, the external symptom will be the load LEDs cycling between on and off as the driver repeatedly overheats and cools, alternately turning the LEDs off and then back on again.
Applications Information
Selecting External Component RSET to Set LED Output Current
The MAX6977 uses an external resistor RSET to set the LED current for outputs OUT0-OUT7. The minimum allowed value of RSET is 307.6, which sets the output currents to 55mA. The maximum allowed value of RSET is 1.5k. The reference value, 360, sets the output currents to 50mA. To set a different output current, use the formula: RSET = 18000 / IOUT where IOUT is the desired output current in mA.
Power-Supply Considerations
The MAX6977 operates with a chip supply V+, and one or more LED supplies. Bypass each supply to GND with a 0.1F capacitor as close to the MAX6977 as possible. This is normally adequate for static LED driving. For multiplex or PWM applications, it is necessary to add an additional bulk electrolytic capacitor of 4.7F or more to each supply for every 4 to 16 MAX6977s. The necessary capacitance depends on the LED load current, PWM switching frequency, and serial interface speed. Inadequate V+ decoupling may cause timing problems, and very noisy LED supplies can affect LED current regulation. For the TSSOP version, connect the underside exposed pad to GND.
Computing Power Dissipation
The upper limit for power dissipation (P D ) for the MAX6977 is determined from the following equation: PD = (V+ x I+) + (VOUT x DUTY x IOUT x N) where: V+ = supply voltage I+ = operating supply current when sinking IOUT LED drive current into N outputs
Chip Information
TRANSISTOR COUNT: 2382 PROCESS: BiCMOS
_______________________________________________________________________________________
9
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
Selector Guide
PART MAX6968 MAX6977 MAX6978 MAX6970 MAX6981 MAX6980 MAX6969 MAX6984 MAX6979 MAX6971 MAX6982 MAX6983 16 36 16 5.5 8 36 55mA 8 5.5 NO. OF OUTPUTS MAX OUTPUT VOLTAGE (V) MAX OUTPUT CURRENT LED FAULT DETECTION -- Yes Yes -- Yes Yes -- Yes Yes -- Yes Yes WATCHDOG -- -- Yes -- -- Yes -- -- Yes -- -- Yes
Typical Application Circuit
5V
+5V
C SCLK MOSI MISO LOAD ENABLE 360
V+ CLK DIN DOUT LATCH OE SET GND
MAX6977
OUT0 OUT1 OUT2 OUT3 OUT4 OUT5 OUT6 OUT7
0V
0V
10
______________________________________________________________________________________
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
TSSOP 4.4mm BODY.EPS
MAX6977
XX XX
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY, EXPOSED PAD
21-0108
E
1
1
______________________________________________________________________________________
11
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection MAX6977
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
12
______________________________________________________________________________________
PDIPN.EPS
8-Port, 5.5V Constant-Current LED Driver with LED Fault Detection
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
MAX6977
2
1
INCHES DIM A A1 B C E H D E e H L MIN 0.068 0.002 0.010 MAX 0.078 0.008 0.015
MILLIMETERS MIN 1.73 0.05 0.25 MAX 1.99 0.21 0.38 D D D D D INCHES MIN 0.239 0.239 0.278 0.317 0.397 MAX 0.249 0.249 0.289 0.328 0.407 MILLIMETERS MIN 6.07 6.07 7.07 8.07 10.07 MAX 6.33 6.33 7.33 8.33 10.33 N 14L 16L 20L 24L 28L
0.20 0.09 0.004 0.008 SEE VARIATIONS 0.205 0.301 0.025 0 0.212 0.311 0.037 8 5.20 7.65 0.63 0 5.38 7.90 0.95 8 0.0256 BSC 0.65 BSC
N
A C e D B A1 L
NOTES: 1. D&E DO NOT INCLUDE MOLD FLASH. 2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006"). 3. CONTROLLING DIMENSION: MILLIMETERS. 4. MEETS JEDEC MO150. 5. LEADS TO BE COPLANAR WITHIN 0.10 MM.
PROPRIETARY INFORMATION TITLE:
PACKAGE OUTLINE, SSOP, 5.3 MM
APPROVAL DOCUMENT CONTROL NO. REV.
21-0056
C
1 1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
SSOP.EPS

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