MBI5027CF

Macroblock Features Preliminary Datasheet MBI5027 16-bit Constant Current LED Sink Driver with Error Detection 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.) · 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 MBI5027CF MBI5016CF MBI5027CP MBI5016CP Current Accuracy Between Channels Between ICs < ±3% < ±6% 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: info@mblock.com.tw -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 Function Description of Pin 4 Function Description of Pin 21 MBI5027 LE + Error Detection (ED1) OE + Error Detection (ED2) -2- April 2003, V0.8-4 MBI5027 Block Diagram 16-bit Constant Current LED Sink Driver with Error Detection OUT0 OUT1 OUT14 OUT15 R-EXT VDD IO Regulator OE(ED2) LE(ED1) GND Control Logic Output Driver & Error Detector 16 16-bit Output Latch 16 16-bit Shift Register 16 SDO CLK SDI Terminal Description Pin No. 1 2 3 Pin Configuration Function 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 Pin Name GND SDI CLK Ground terminal for control logic and current sink Serial-data input to the Shift Register Clock input terminal for data shift on rising edge Data strobe input terminal Serial data is transferred to the respective latch when LE(ED1) is high. The data is latched when LE(ED1) goes low. Also, a control signal input for Error Detection mode (See Timing Diagram) 4 LE(ED1) 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 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 -3April 2003, V0.8-4 23 24 R-EXT VDD MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Equivalent Circuits of Inputs and Outputs OE(ED2) terminal VDD LE(ED1) terminal VDD IN IN CLK, SDI terminal VDD SDO terminal VDD IN OUT -4- April 2003, V0.8-4 MBI5027 Timing Diagram Normal Mode N=0 1 2 3 16-bit Constant Current LED Sink Driver with Error Detection 4 5 6 7 8 9 10 11 12 13 14 15 CLK SDI LE(ED2) OE(ED2) OUT0 OUT1 OUT2 OUT3 OFF ON OFF ON OFF ON OFF ON OFF OUT15 SDO ON : don’t care Truth Table (In Normal Mode) CLK LE H L H X X OE L L L L H SDI Dn Dn+1 Dn+2 Dn+3 Dn+3 OUT0 … OUT 7 … OUT15 Dn …. Dn - 7 …. Dn - 15 No Change Dn + 2 …. Dn - 5 …. Dn - 13 SDO Dn-15 Dn-14 Dn-13 Dn-13 Dn-13 Dn + 2 …. Dn - 5 …. Dn - 13 Off -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) LE(ED1) 1 0 0 0 1 0 1 1 1 0 The signal sequence makes MBI5027 enter an Error Detection mode. Reading Error Status Code CLK OE (ED2) SDO about 2 μs Error Status Code Bit15 Bit14 Bit13 Bit12 Bit11 : don’t care A system controller can read Error Status codes through SDO pin. Resuming to Normal Mode 1 2 3 4 5 CLK OE(ED2) LE(ED1) 1 0 0 0 1 0 1 0 1 0 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 Supply Voltage Input Voltage Output Current Output Voltage Clock Frequency GND Terminal Current CNS – type Power Dissipation (On PCB, Ta=25°C) CF – type CP – type CNS – type Thermal Resistance (On PCB, Ta=25°C) Operating Temperature Storage Temperature CF – type CP – type Topr Tstg Rth(j-a) PD Symbol VDD VIN IOUT VDS FCLK IGND Rating 0~7.0 -0.4~VDD + 0.4 +90 -0.5~+20.0 25 1440 1.52 1.30 1.11 82 96 112 -40~+85 -55~+150 °C °C °C/W W Unit V V mA V MHz mA -7- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Recommended Operating Conditions Characteristic Supply Voltage Output Voltage Symbol VDD VDS IOUT Output Current IOH IOL Input Voltage VIH VIL LE(ED1) Pulse Width CLK Pulse Width OE (ED2) Pulse Width Setup Time for SDI Hold Time for SDI Setup Time for LE(ED1) Hold Time for LE(ED1) OE (ED2) Pulse Width CLK Pulse Width Setup Time for LE(ED1) Hold Time for LE(ED1) Setup Time for OE (ED2) Hold Time for OE (ED2) Clock Frequency tw(L) tw(CLK) tw(OE) tsu(D) th(D) tsu(L) th(L) tw(ED2) tw(CLK) tsu(ED1) th(ED1) tsu(ED2) th(ED2) FCLK Cascade Operation Ta=85°C (CNS type) Power Dissipation PD Ta=85°C (CF type) Ta=85°C (CP type) Error Detection Mode VDD=4.5~5.5V Normal Mode VDD=4.5~5.5V Condition Min. 4.5 5 0.8VDD -0.3 40 20 200 5 10 15 15 2 20 5 10 5 10 Typ. 5.0 Max. 5.5 17.0 60 -1.0 1.0 VDD+0.3 0.3VDD 25.0 0.79 0.67 0.57 W Unit V V mA mA mA V V ns ns ns ns ns ns ns us ns ns ns ns ns MHz OUT0 ~ OUT15 DC Test Circuit SDO SDO CLK, OE (ED2), LE(ED1) and SDI CLK, OE (ED2), LE(ED1) and SDI -8- April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Electrical Characteristics Characteristic Input Voltage “H” level “L” level Symbol VIH VIL IOH VOL VOH IOUT1 dIOUT1 IOUT2 dIOUT2 %/dVDS %/dVDD RIN(up) RIN(down) VDS, Th1 Open Circuit Error*** Discrimination Voltage VDS, Th2 VDS, Th3 VDS, Th4 IDD(off) 1 “OFF” Supply Current “ON” IDD(off) 2 IDD(off) 3 IDD(on) 1 IDD(on) 2 Condition Ta = -40~85ºC Ta = -40~85ºC VOH=17.0V IOL=+1.0mA IOH=-1.0mA VDS=0.6V IOL=25mA VDS=0.6V VDS=0.8V IOL=50mA VDS=0.8V Rext=720 Ω Rext=720 Ω Rext=360 Ω Rext=360 Ω Min. 0.8VDD GND 4.6 Typ. 25.0 Max. VDD 0.3VDD 0.5 0.4 Unit V V μA V V mA Output Leakage Current Output Voltage SDO Output Current 1 Current Skew - ±1 ±3 % Output Current 2 Current Skew Output Current vs. Output Voltage Regulation Output Current vs. Supply Voltage Regulation Pull-up Resistor Pull-down Resistor - 50.0 - mA 250 250 1.0 0.8 1.2 1.0 - ±1 ±0.1 ±1 500 500 9 11 14 11 14 ±3 800 800 - % %/V %/V KΩ KΩ V V V V VDS within 1.0V and 3.0V VDD within 4.5V and 5.5V OE (ED2) LE(ED1) W hen all output ports sink 20mA simultaneously W hen a single output port sinks 20mA W hen all output ports sink 50mA simultaneously W hen a single output port sinks 50mA Rext=Open, OUT0 ~ OUT15 =Off Rext=720 Ω, OUT0 ~ OUT15 =Off Rext=360 Ω, OUT0 ~ OUT15 =Off Rext=720 Ω, OUT0 ~ OUT15 =On Rext=360 Ω, OUT0 ~ OUT15 =On 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) IOUT OUT0 IIH,IIL CLK LE(ED1) SDI R - EXT GND . . . . OUT15 SDO VIH, VIL Iref - 10 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Switching Characteristics Characteristic CLK - OUTn Propagation Delay Time LE(ED1) - OUTn (“L” to “H”) OE (ED2) - OUTn CLK - SDO CLK - OUTn Propagation Delay Time (“H” to “L”) LE(ED1) - OUTn OE (ED2) - OUTn CLK - SDO CLK Pulse Width LE(ED1) OE (ED2) Hold Time for LE(ED1) Setup Time for LE(ED1) Maximum CLK Rise Time Maximum CLK Fall Time Output Rise Time of Iout Output Fall Time of Iout Symbol tpLH1 tpLH2 tpLH3 tpLH tpHL1 tpHL2 tpHL3 tpHL tw(CLK) tw(L) tw(OE) th(L) tsu(L) tr** tf** tor tof 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 Condition Min. 15 15 20 20 200 5 5 Typ. 50 50 20 20 100 100 50 20 70 40 Max. 100 100 100 150 150 150 500 500 200 120 Unit ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns **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 VDD OE(ED2) CLK LE(ED1) SDI R - EXT GND IOUT OUT0 Function Generator . . . OUT15 SDO RL CL VL Logic input waveform VIH = 5V VIL = 0V tr = tf = 10 ns Iref CL - 11 - April 2003, V0.8-4 MBI5027 Timing Waveform Normal Mode 16-bit Constant Current LED Sink Driver with Error Detection tW(CLK) CLK 50% 50% 50% tsu(D) th(D) 50% SDI 50% SDO tpLH, tpHL 50% tW(L) 50% 50% LE(ED1) th(L) tsu(L) LOW = OUTPUTS ENABLED HIGH = OUTPUT OFF OE(ED2) OUTn 50% tpLH1, tpHL1 LOW = OUTPUT ON tpLH2, tpHL2 tW(OE) 50% 50% OE(ED2) tpHL3 90% 50% 10% tpLH3 90% 50% 10% OUTn tof tor - 12 - April 2003, V0.8-4 MBI5027 16-bit Constant Current LED Sink Driver with Error Detection Entering Error Detection Mode tW(CLK) CLK 50% 50% 50% 50% 50% tsu(ED2) th(ED2) OE(ED2) 50% 50% tsu(ED1) th(ED1) 50% LE(ED1) 2 CLK 50% Reading Error Status Code CLK 50% 50% OE(ED2) 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 90.00 80.00 Iout (mA) 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 60 50 40 30 20 10 0 0 500 1000 1500 2000 2500 3000 3500 4000 VDS = 1.0V 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) LE(ED1) 1 0 0 0 1 0 1 1 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 2 μs 0 1 1 1 1 OE(ED2) SDO 1 0 0 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 CLK OE(ED2) LE(ED1) 1 0 0 0 1 0 1 0 1 0 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 N0 -1 SDI, 0 MBI5027, MBI5027, 1 MBI5027, 2 CLK LE(ED1) OE (ED2) 1 CLK SDI, 0 N-1 N x 16 -1 LE(ED1) Serial Data (Note 1) LE(ED1) SDI, 0 2 1 0 T1 = 2 CLK T2 = 2µs Don’t Care Could Be “Don’t Care” SDI, 0 2 3 4 5 N x 16 CLK Pulses (Note 1) th(L) 3 CLK Pulses Required (Note 2) N x 16 CLK Pulses (Note 3) 1 2 3 4 5 LED j, j = 0… (N x16 –1) SDO, N-1 N-1 MBI5027, N-2 MBI5027, N-1 OE (ED2) OE (ED2) T3 (Note 2) SDO, 0 N-1 SDO, 1 15 31 14 30 N x 1 6 -2 A Entering the Error Detection Mode B C SDO, N-1 N-1 N x 16 2 D Reading Back the Error Status Code 1 0 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. 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 - 18 - 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) Iout vs. Duty Cycle at Rth = 82 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 5% 10% 15% Iout (mA) Ta = 25°C Ta = 55°C Ta = 85°C 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 95% 100% 100% Duty Cycle For CF type package, the thermal resistance is Rth(j-a) = 96 (°C/W) Iout vs. Duty Cycle at Rth = 96 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 5% 10% 15% Iout (mA) Ta = 25 ℃ Ta = 55 ℃ Ta = 85 ℃ 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 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) Iout vs. Duty Cycle at Rth = 112 (°C/W) 100 90 80 70 60 50 40 30 20 10 0 5% 10% Iout (mA) Ta = 25°C Ta = 55°C Ta = 85°C 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100% 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 50 I out ( m A ) 40 30 20 10 0 5% 10% 15% Ta = 25°C Ta = 55°C Ta = 85°C 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100% 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 50 Iout (mA) 40 30 20 10 0 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100% Ta = 25°C Ta = 55°C Ta = 85°C 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 50 Iout (mA) 40 30 20 10 0 5% 10% 15% 20% Ta = 25°C Ta = 55°C Ta = 85°C 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100% 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 1.4 Power Dissipation 1.2 1 0.8 0.6 0.4 0.2 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 CNS Type: Rth = 82 CF Type: Rth = 96 CP Type: Rth = 112 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 VDROP VLED VDROP Vf VDS Vf 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