MBI5027 Preliminary Datasheet Macroblock 16-bit Constant Current LED Sink Driver with Error Detection Features MBI5027CNS MBI5016CNS · Error Detection mode to detect LED open-circuit errors · 16 constant-current output channels · Constant output current invariant to load voltage change · Excellent output current accuracy: between channels: ±3% (max.), and between ICs: ±6% (max.) MBI5027CF MBI5016CF · Output current adjusted through an external resistor · Constant output current range: 5-90 mA · Fast response of output current, OE (min.): 200 ns · 25MHz clock frequency · Schmitt trigger input · 5V supply voltage Current Accuracy Between Channels Between ICs < ±3% < ±6% MBI5027CP MBI5016CP Conditions IOUT = 10 mA ~ 60 mA ÓMacroblock, Inc. 2003 Floor 6-4, No.18, Pu-Ting Rd., Hsinchu, Taiwan 30077, ROC. TEL: +886-3-579-0068, FAX: +886-3-579-7534 E-mail: [email protected] -1- MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Product Description MBI5027 succeeds MBI5026 and is designed for LED displays with open-circuit Error Detection extension. MBI5027 exploits PrecisionDrive™ technology to enhance its output characteristics. MBI5027 contains a serial buffer and data latches, which convert serial input data into parallel output format. At MBI5027 output stage, sixteen regulated current ports are designed to provide uniform and constant current sinks for driving LEDs within a wide range of Vf variations. While MBI5027 is used in their system design for LED display applications, e.g. LED panels, it provides users with great flexibility and device performance. Users may adjust the output current from 5 mA to 90 mA through an external resistor, Rext, which gives users flexibility in controlling the light intensity of LEDs. MBI5027 guarantees to endure maximum 17V at the output port. The high clock frequency, 25 MHz, also satisfies the system requirements of high volume data transmission. MBI5027 exploits the idea of Share-I-O™ technology to extend its performance;in addition, MBI5027 is backward compatible with MBI5026 in both electrical characteristics and package aspect. With Share-I-O™ technology, users can, without changing the printed circuit board originally for MBI5026, let MBI5027 enter a special function mode, an Error Detection mode, just by setting a sequence of signals on LE(ED1), OE (ED2) and CLK input pins. In the Error Detection mode, MBI5027 detects the status of individual LED connected to MBI5027. The status will be saved in a built-in register. Then, a system controller may read, through SDO pin, the error status from the register to know whether LEDs are properly lit or not. By setting another sequence of signals on LE(ED1), OE (ED2) and CLK input pins, MBI5027 may resume to a Normal mode and perform as MBI5026. In Application Information, users can get detailed ideas about how MBI5027 works in the Error Detection mode. A Share-I-O™ technique is specifically applied to MBI5027. By means of the Share-I-O™ technique, an additionally effective function, Error Detection, can be added to LED drivers, however, without any extra pins. Thus, MBI5027 could be a drop-in replacement of MBI5026. The printed circuit board originally designed for MBI5026 may be also applicable for MBI5027. For MBI5027, the pin 4, LE(ED1), and the pin 21, OE (ED2), can be acted as different functions as follows: Pin Device Name MBI5027 Function Description of Pin 4 LE + Error Detection (ED1) Function Description of Pin 21 OE + Error Detection (ED2) -2- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Block Diagram OUT0 OUT1 OUT14 OUT15 IO Regulator R-EXT VDD OE(ED2) Control Logic Output Driver & Error Detector LE(ED1) 16 GND 16-bit Output Latch CLK 16 16-bit Shift Register SDI SDO 16 Terminal Description Pin Configuration Pin No. Pin Name Function 1 GND Ground terminal for control logic and current sink 2 SDI Serial-data input to the Shift Register 3 CLK Clock input terminal for data shift on rising edge Data strobe input terminal 4 LE(ED1) Serial data is transferred to the respective latch when LE(ED1) is high. The data is latched when LE(ED1) goes low. GND SDI CLK LE(ED1) OUT0 OUT1 OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 VDD R-EXT SDO OE(ED2) OUT15 OUT14 OUT13 OUT12 OUT11 OUT10 OUT9 OUT8 Also, a control signal input for Error Detection mode (See Timing Diagram) 5~20 OUT0 ~ OUT15 Constant current output terminals Output enable terminal 21 OE (ED2) When (active) low, the output drivers are enabled; when high, all output drivers are turned OFF (blanked). Also, a control signal input for Error Detection mode (See Timing Diagram) 22 SDO 23 R-EXT 24 VDD Serial-data output to the following SDI of next driver IC Input terminal used to connect an external resistor for setting up all output current 5V supply voltage terminal -3- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Equivalent Circuits of Inputs and Outputs OE(ED2) terminal LE(ED1) terminal VDD VDD IN IN CLK, SDI terminal SDO terminal VDD VDD OUT IN -4- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Timing Diagram Normal Mode N=0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CLK SDI LE(ED2) OE(ED2) OFF OUT0 ON OFF OUT1 ON OFF OUT2 ON OFF OUT3 ON OFF OUT15 ON SDO : don’t care Truth Table (In Normal Mode) CLK LE OE SDI OUT0 … OUT 7 … OUT15 SDO H L Dn Dn …. Dn - 7 …. Dn - 15 Dn-15 L L Dn+1 No Change Dn-14 H L Dn+2 Dn + 2 …. Dn - 5 …. Dn - 13 Dn-13 X L Dn+3 Dn + 2 …. Dn - 5 …. Dn - 13 Dn-13 X H Dn+3 Off Dn-13 -5- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Entering Error Detection Mode 1 2 3 4 5 CLK OE(ED2) 1 0 1 1 1 LE(ED1) 0 0 0 1 0 The signal sequence makes MBI5027 enter an Error Detection mode. Reading Error Status Code CLK about 2 μs OE (ED2) SDO Error Status Code : don’t care Bit15 Bit14 Bit13 Bit12 Bit11 A system controller can read Error Status codes through SDO pin. Resuming to Normal Mode 1 2 3 4 5 OE(ED2) 1 0 1 1 1 LE(ED1) 0 0 0 0 0 CLK Voltage “Low” The signal sequence makes MBI5027 resume to the Normal mode. Note: If users want to know the whole process, that is how to enter the Error Detection mode, read Error Status codes and resume to the Normal mode, please refer to the contents in Application Information. -6- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Maximum Ratings Characteristic Symbol Rating Unit Supply Voltage VDD 0~7.0 V Input Voltage VIN -0.4~VDD + 0.4 V Output Current IOUT +90 mA Output Voltage VDS -0.5~+20.0 V Clock Frequency FCLK 25 MHz GND Terminal Current IGND 1440 mA CNS – type Power Dissipation (On PCB, Ta=25°C) Thermal Resistance (On PCB, Ta=25°C) 1.52 PD CF – type 1.30 CP – type 1.11 CNS – type 82 Rth(j-a) CF – type CP – type 96 W °C/W 112 Operating Temperature Topr -40~+85 °C Storage Temperature Tstg -55~+150 °C -7- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Recommended Operating Conditions Characteristic Symbol Condition Min. Typ. Max. Unit Supply Voltage VDD - 4.5 5.0 5.5 V Output Voltage VDS OUT0 ~ OUT15 - - 17.0 V IOUT DC Test Circuit 5 - 60 mA IOH SDO - - -1.0 mA IOL SDO - - 1.0 mA VIH CLK, OE (ED2), LE(ED1) and SDI CLK, OE (ED2), LE(ED1) and SDI 0.8VDD - VDD+0.3 V -0.3 - 0.3VDD V tw(L) 40 - - ns CLK Pulse Width tw(CLK) 20 - - ns OE (ED2) Pulse Width tw(OE) 200 - - ns 5 - - ns Output Current Input Voltage VIL LE(ED1) Pulse Width Normal Mode VDD=4.5~5.5V Setup Time for SDI tsu(D) Hold Time for SDI th(D) 10 - - ns Setup Time for LE(ED1) tsu(L) 15 - - ns Hold Time for LE(ED1) th(L) 15 - - ns OE (ED2) Pulse Width tw(ED2) 2 - - us CLK Pulse Width tw(CLK) 20 - - ns 5 - - ns 10 - - ns Setup Time for LE(ED1) tsu(ED1) Hold Time for LE(ED1) th(ED1) Setup Time for OE (ED2) tsu(ED2) 5 - - ns Hold Time for OE (ED2) th(ED2) 10 - - ns Clock Frequency FCLK Cascade Operation - - 25.0 MHz Ta=85°C (CNS type) - - 0.79 Ta=85°C (CF type) - - 0.67 Ta=85°C (CP type) - - 0.57 Power Dissipation PD Error Detection Mode VDD=4.5~5.5V -8- W April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Electrical Characteristics Characteristic Input Voltage Symbol Condition Min. Typ. Max. Unit “H” level VIH Ta = -40~85ºC 0.8VDD - VDD V “L” level VIL Ta = -40~85ºC GND - 0.3VDD V IOH VOH=17.0V - - 0.5 μA VOL IOL=+1.0mA - - 0.4 V VOH IOH=-1.0mA 4.6 - - V Output Leakage Current Output Voltage SDO Output Current 1 IOUT1 VDS=0.6V Rext=720 Ω - 25.0 - mA Current Skew dIOUT1 IOL=25mA VDS=0.6V Rext=720 Ω - ±1 ±3 % Output Current 2 IOUT2 VDS=0.8V Rext=360 Ω - 50.0 - mA Current Skew dIOUT2 IOL=50mA VDS=0.8V Rext=360 Ω - ±1 ±3 % Output Current vs. Output Voltage Regulation %/dVDS VDS within 1.0V and 3.0V - ±0.1 - %/V Output Current vs. Supply Voltage Regulation %/dVDD VDD within 4.5V and 5.5V - ±1 - %/V RIN(up) OE (ED2) 250 500 800 KΩ RIN(down) LE(ED1) 250 500 800 KΩ Pull-up Resistor Pull-down Resistor Open Circuit Error*** Discrimination Voltage “OFF” Supply Current “ON” VDS, Th1 When all output ports sink 20mA simultaneously 1.0 - - V VDS, Th2 When a single output port sinks 20mA 0.8 - - V VDS, Th3 When all output ports sink 50mA simultaneously 1.2 - - V VDS, Th4 When a single output port sinks 50mA 1.0 - - V IDD(off) 1 Rext=Open, OUT0 ~ OUT15 =Off - 9 - IDD(off) 2 Rext=720 Ω, OUT0 ~ OUT15 =Off - 11 - IDD(off) 3 Rext=360 Ω, OUT0 ~ OUT15 =Off - 14 - IDD(on) 1 Rext=720 Ω, OUT0 ~ OUT15 =On - 11 - IDD(on) 2 Rext=360 Ω, OUT0 ~ OUT15 =On - 14 - mA *** To effectively detect the error occurring at the output port, MBI5027 has a built-in current detection circuit. The current detection circuit will detect the effective current IOUT, effective, and compare the effective current IOUT, effective, to the target current IOUT, target, defined by Rext. If IOUT, effective, is much less than the target current IOUT, target, an error flag will be asserted in the built-in Shift Register. The minimum voltage requirement for such current detection is VDS, Th1, VDS, Th2, VDS, Th3 and VDS, Th4. -9- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Test Circuit for Electrical Characteristics IDD VDD OE(ED2) IIH,IIL CLK LE(ED1) IOUT .. .. OUT0 OUT15 SDI R - EXT GND SDO VIH, VIL Iref - 10 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Switching Characteristics Characteristic Symbol CLK - OUTn Propagation Delay Time LE(ED1) - OUTn (“L” to “H”) OE (ED2) - OUTn CLK - SDO Condition Min. Typ. Max. Unit tpLH1 - 50 100 ns tpLH2 - 50 100 ns tpLH3 - 20 100 ns 15 20 - ns - 100 150 ns - 100 150 ns - 50 150 ns 15 20 - ns 20 - - ns 20 - - ns tpLH VDD=5.0 V VDS=0.8 V VIH=VDD VIL=GND Rext=300 Ω VL=4.0 V RL=52 Ω CL=10 pF CLK - OUTn tpHL1 LE(ED1) - OUTn tpHL2 OE (ED2) - OUTn tpHL3 CLK - SDO tpHL CLK tw(CLK) LE(ED1) tw(L) OE (ED2) tw(OE) 200 - - ns Hold Time for LE(ED1) th(L) 5 - - ns Setup Time for LE(ED1) tsu(L) 5 - - ns Maximum CLK Rise Time tr** - - 500 ns Maximum CLK Fall Time tf** - - 500 ns Output Rise Time of Iout tor - 70 200 ns Output Fall Time of Iout tof - 40 120 ns Propagation Delay Time (“H” to “L”) Pulse Width **If the devices are connected in cascade and tr or tf is large, it may be critical to achieve the timing required for data transfer between two cascaded devices. Test Circuit for Switching Characteristics IDD VIH, VIL Function Generator VDD OE(ED2) CLK LE(ED1) SDI R - EXT GND IOUT .. . OUT0 OUT15 RL SDO CL Logic input waveform VIH = 5V VL CL Iref VIL = 0V tr = tf = 10 ns - 11 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Timing Waveform Normal Mode tW(CLK) tsu(D) SDI 50% 50% CLK 50% 50% th(D) 50% SDO 50% tW(L) tpLH, tpHL LE(ED1) 50% 50% th(L) OE(ED2) tsu(L) LOW = OUTPUTS ENABLED HIGH = OUTPUT OFF 50% OUTn tpLH1, tpHL1 LOW = OUTPUT ON tpLH2, tpHL2 tW(OE) 50% OE(ED2) 50% tpLH3 tpHL3 90% 50% 10% OUTn tof - 12 - 90% 50% 10% tor April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Entering Error Detection Mode tW(CLK) 50% 50% CLK 50% 50% 50% tsu(ED2) th(ED2) OE(ED2) 50% 50% tsu(ED1) LE(ED1) 50% th(ED1) 50% 2 CLK Reading Error Status Code 50% CLK OE(ED2) 50% 50% 50% tw(ED2) - 13 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Application Information Constant Current To design LED displays, MBI5027 provides nearly no variations in current from channel to channel and from IC to IC. This can be achieved by: 1) The maximum current variation between channels is less than ±3% and that between ICs is less than ±6%. 2) In addition, the current characteristic of output stage is flat and users can refer to the figure as shown below. The output current can be kept constant regardless of the variations of LED forward voltages (Vf). This performs as a complete function of the load regulation. 100.00 Iout (mA) 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 2 2.5 VDS (V) - 14 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Adjusting Output Current The output current of each channel (IOUT) is set by an external resistor, Rext. The relationship between Iout and Rext is shown in the following figure. IOUT (mA) 100 90 80 70 VDS = 1.0V 60 50 40 30 20 10 0 0 500 1000 1500 2000 2500 3000 3500 4000 Resistance of the external resistor, Rext, in Ω Also, the output current in milliamps can be calculated from the equation: IOUT is (625/ Rext) x 28.8, approximately, where Rext, in Ω, is the resistance of the external resistor connected to R-EXT terminal. The magnitude of current is around 50mA at 360Ω and 25mA at 720Ω. - 15 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Entering Error Detection Mode 1 2 3 4 5 CLK OE(ED2) 1 0 1 1 1 LE(ED1) 0 0 0 1 0 Each time the system controller sends the sequence patterns shown above, MBI5027 can enter the Error Detection mode. During this phase, the system controller can still send data through SDI pin. The state of OE (ED2) and LE(ED1) is sampled by the rising edge of each CLK. We use “0” and “1” to represent the state of “Voltage Low” and “Voltage High” respectively. The states of the successive five OE (ED2) and LE(ED1) are (1, 0), (0, 0), (1, 0), (1, 1) and (1, 0). Reading Error Status Code CLK about OE(ED2) SDO 1 0 0 2 μs 0 1 1 1 1 Error Status Code Bit15 Bit14 Bit13 Bit12 Bit11 Once entering the Error Detection mode, the Error Detection takes place by changing the state of OE (ED2) from “Voltage High” to “Voltage Low”. The built-in current detection circuit will detect the effective current IOUT, effective of each output channel, and compare it to the target current IOUT, target, defined by Rext. If the IOUT, effective , is much less than the target current IOUT, target, an error status code will be represented as “0” state. During the period of detecting errors, data cannot be sent into MBI5027 through SDI pin. The “Voltage Low” state of OE (ED2) requires at least three “0” of which the last “0” should be at least 2μs after the falling edge of OE (ED2). The occurrence of the last “0” results in the event that MBI5027 saves the error status in the built-in register. The mentioned state of each “0” is sampled by the rising edge of each CLK. Before the error status saved in the built-in register is read, the state of OE (ED2) should be pulled up from “Voltage Low” to “Voltage High”. Then, by sending CLK, MBI5027 shifts out, through SDO pin, the error status bit by bit. - 16 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Resuming to Normal Mode 1 2 3 4 5 OE(ED2) 1 0 1 1 1 LE(ED1) 0 0 0 0 0 CLK Voltage “Low” Each time the system controller sends the sequence patterns shown above, MBI5027 can resume to the Normal mode. During this phase, the system controller can still send data through SDI pin. The state of OE (ED2) and LE(ED1) is sampled by the rising edge of each CLK. We use “0” and “1” to represent the state of “Voltage Low” and “Voltage High” respectively. The states of the successive five OE (ED2) and LE(ED1) are (1, 0), (0, 0), (1, 0), (1, 0) and (1, 0). - 17 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Timing Chart for Error Detection Mode (An Example) N x MBI5027 are connected in cascade, ie, SDO, k --> SDI, k+1. And, all MBI5027 ICs are connected to the same CLK, LE(ED1) and OE (ED2) signals. SDO, 2 SDO, 0 SDI, 1 SDO, 1 N-1 SDI, 0 MBI5027, 0 MBI5027, 1 MBI5027, 2 LED j, j = 0… (N x16 –1) MBI5027, N-2 MBI5027, N-1 SDO, N-1 N-1 CLK LE(ED1) OE (ED2) 1 2 3 4 5 th(L) N x 16 CLK Pulses (Note 1) 3 CLK Pulses Required (Note 2) N x 16 CLK Pulses (Note 3) 1 2 3 4 5 CLK SDI, 0 N-1 SDI, 0 N x 16 -1 Don’t Care 2 Serial Data (Note 1) LE(ED1) LE(ED1) OE (ED2) OE (ED2) 1 0 SDI, 0 Could Be “Don’t Care” T1 = 2 CLK T2 = 2µs T3 (Note 2) SDO, 0 N-1 SDO, 1 15 14 31 30 N x 16 -2 A Entering the Error Detection Mode B C SDO, N-1 N-1 Detecting the Error Status Sending the Normal Image Data (or Test Data) Serial Data k, k = 0… (N x 16 –1) Note 2: T1 = 2 CLK pluses is required to start the error detection. Note 1: N x 16 CLK pulses before the T2 = 2 μs is required to obtain the stable error status result. next LE shift the valid image data. N x T3 = the third CLK pulses is required before OE (ED2) goes 16 “1”s are suggested. voltage high. The rising edge of CLK writes the error status code back to the MBI5027 built-in shift register. - 18 - 2 N x 16 1 0 D Reading Back the Error Status Code Resuming to the Normal Mode Note 3: The first rising edge of CLK after the rising edge of OE (ED2) starts shifting the Image Data with LED Error. An LED error will be represented by a “0”, to over write the original image data “1”. Image Data k, k = 0… (N x 16 –1), = all “1” is suggested. N x 16 CLK pulses shift all N x 16 error results (Error Status Code) via Node SDO, N April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Package Power Dissipation (PD) The maximum allowable package power dissipation is determined as PD(max) = (Tj – Ta) / Rth(j-a). When 16 output channels are turned on simultaneously, the actual package power dissipation is PD(act) = (IDD x VDD) + (IOUT x Duty x VDS x 16). Therefore, to keep PD(act) ≤ PD(max), the allowable maximum output current as a function of duty cycle is: IOUT = { [ (Tj – Ta) / Rth(j-a) ] – (IDD x VDD) } / VDS / Duty / 16, where Tj = 150°C. (A) Iout = 90mA, VDS = 1.0V, 16 output channels active For CNS type package, the thermal resistance is Rth(j-a) = 82 (°C/W) Ta = 25°C Ta = 55°C 95% 100% 95% 100% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% Ta = 85°C 5% Iout (mA) Iout vs. Duty Cycle at Rth = 82 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 Duty Cycle For CF type package, the thermal resistance is Rth(j-a) = 96 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 Ta = 25 ℃ Ta = 55 ℃ 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% Ta = 85 ℃ 5% Iout (mA) Iout vs. Duty Cycle at Rth = 96 (°C/W) Duty Cycle - 19 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection For CP type package, the thermal resistance is Rth(j-a) = 112 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 Ta = 25°C Ta = 55°C 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% Ta = 85°C 5% Iout (mA) Iout vs. Duty Cycle at Rth = 112 (°C/W) Duty Cycle (B) Iout = 60mA, VDS = 0.8V, 16 output channels active For CNS type package, the thermal resistance is Rth(j-a) = 82 (°C/W) Iout vs. Duty Cycle at Rth = 82 (°C/W) 70 60 40 Ta = 25°C 30 20 Ta = 55°C 10 Ta = 85°C 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 0 5% Iout (mA) 50 Duty Cycle - 20 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection For CF type package, the thermal resistance is Rth(j-a)= 96 (°C/W) Iout vs. Duty Cycle at Rth = 96 (°C/W) 70 60 Iout (mA) 50 Ta = 25°C 40 30 Ta = 55°C 20 Ta = 85°C 10 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 5% 10% 0 Duty Cycle For CP type package, the thermal resistance is Rth(j-a) = 112 (°C/W) Iout vs. Duty Cycle at Rth = 112 (°C/W) 70 60 40 Ta = 25°C 30 20 Ta = 55°C 10 Ta = 85°C 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 0 5% Iout (mA) 50 Duty Cycle - 21 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection The maximum power dissipation, PD(max) = (Tj-Ta) / Rth(j-a) , decreases as the ambient temperature increases. Max. Power Dissipation at Various Ambient Temperature 1.6 Power Dissipation 1.4 1.2 1 CNS Type: Rth = 82 0.8 CF Type: Rth = 96 0.6 CP Type: Rth = 112 0.4 0.2 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Ambient Temperature Load Supply Voltage (VLED) MBI5027 are designed to operate with V DS ranging from 0.4V to 1.0V considering the package power dissipating limits. V DS may be higher enough to make PD(act) > PD(max) when VLED = 5V and VDS = VLED – Vf, in which VLED is the load supply voltage. In this case, it is recommended to use the lowest possible supply voltage or to set an external voltage reducer, VDROP. A voltage reducer lets VDS = (VLED – Vf) – VDROP. Resistors or Zener diode can be used in the applications as the following figures. VLED VLED VDROP VDROP Vf Vf VDS VDS MBI5027 MBI5027 - 22 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Package Outlines MBI5027CNS Outline Drawing SDIP-24-P-300-1.78 Units: mm Weight: 1.11g (typ) MBI5027CF Outline Drawing SOP-24-P-300-1.00 Units: mm Weight: 0.28g (typ) - 23 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection MBI5027CP Outline Drawing SSOP24-P-150-0.64 Units: mm Weight: 0.11g (typ) - 24 - April 2003, V0.8-4