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Contents

README

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BD81A44EFV-ME2

ROHM Semicon · LED Drivers · HTSSOP-28-EP

BD81A44EFV-ME2 from ROHM Semicon, in a HTSSOP-28-EP. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 VCC power_in Input power supply pin.
2 SS passive Soft start capacitor connection.
3 COMP output Error amplifier output.
4 RT passive Oscillation frequency setting resistor connection.
5 SYNC input External synchronization input pin.
6 SHDETEN input Short detection enable signal input.
7 GND power_in Small signal GND pin.
8 PWM input PWM light modulation signal input pin.
9 FAIL1 output Failure signal output pin 1.
10 FAIL2 output Failure signal output pin 2.
11 LEDEN1 input Enable pin 1 for LED output.
12 LEDEN2 input Enable pin 2 for LED output.
13 LED1 output LED output pin 1.
14 LED2 output LED output pin 2.
15 LED3 output LED output pin 3.
16 LED4 output LED output pin 4.
17 OVP input Over voltage detection pin.
18 ISET passive LED output current setting pin.
19 PGND power_in LED output GND pin.
20 OUTL output Low side FET gate pin.
21 DGND power_in DC/DC converter output GND pin.
22 VDISC passive Output voltage discharge pin.
23 SW passive High side FET source pin.
24 OUTH output High side FET gate pin.
25 BOOT power_in High side FET driver power supply pin.
26 VREG power_out Internal constant voltage output.
27 EN input Enable pin.
28 CS input DC/DC converter current sense pin.
29 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer ROHM Semicon
Package HTSSOP-28-EP
Category Display Modules / LED Drivers / Display Drivers
Pins 29

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Power Supply Voltage VCC 4.5 12 35 V 14
Operating Temperature Topr -40 25 125 °C 14
DC/DC Oscillation Frequency fOSC 200 300 2200 kHz 14
External Synchronized Pulse Duty DSYNC 40 50 60 % 14
VREG Capacity CVREG 1 2.2 4.7 μF 14
LED Current Setting Resistance RISET 41 100 250 kΩ 14
Oscillation Frequency Setting Resistance RRT 3.6 27 41 kΩ 14
Soft Start Capacity Setting CSS 0.047 0.1 0.47 μF 14
Circuit Current ICC 10 mA EN = High, SYNC = High, RT = OPEN, PWM = Low, ISET = OPEN, CIN = 10 μF 15
Standby Current IST 10 μA EN = Low, VDISC = OPEN 15
Reference Voltage VVREG 4.5 5 5.5 V IVREG = -5 mA, CVREG = 2.2 μF 15
OUTH High Side ON-Resistor RONHH 1.5 3.5 7 Ω IOUTH = -10 mA 15
OUTH Low Side ON-Resistor RONHL 0.8 2.5 5.5 Ω IOUTH = 10 mA 15
OCP Detection Voltage VOLIMIT -0.22 -0.2 -0.18 V Printed as VCC-0.22 / VCC-0.20 / VCC-0.18 V (relative to VCC) 15
OUTL High Side ON-Resistor RONLH 1.5 3.5 10 Ω IOUTL = -10 mA 15
OUTL Low Side ON-Resistor RONLL 0.8 2.5 5.5 Ω IOUTL = 10 mA 15
SW ON-Resistor RON_SW 4 10 25 Ω ISW = 10 mA 15
LED Control Voltage VLED 0.9 1 1.1 V 15
COMP Sink Current ICOMPSINK 35 80 145 μA VLEDn = 2 V (n = 1 to 4), VCOMP = 1 V 15
COMP Source Current ICOMPSOUCE -145 -80 -35 μA VLEDn = 0.5 V (n = 1 to 4), VCOMP = 1 V 15
Oscillation Frequency 1 fOSC1 285 300 315 kHz RRT = 27 kΩ 15
Oscillation Frequency 2 fOSC2 1800 2000 2200 kHz RRT = 3.9 kΩ 15
OVP Detection Voltage VOVP1 1.9 2 2.1 V VOVP: Sweep up 15
OVP Hysteresis Width VOVPHYS1 0.02 0.06 0.1 V VOVP: Sweep down 15
UVLO Detection Voltage VUVLO 3.2 3.5 3.8 V VCC: Sweep down 16
UVLO Hysteresis Width VUHYS 0.25 0.5 0.75 V VCC: Sweep up, VVREG > 3.5 V 16
LED Current Relative Dispersion ΔILED1 -3 3 % ILED = 50 mA, Ta = 25 °C 16
LED Current Relative Dispersion ΔILED1 -5 5 % ILED = 50 mA, Ta = -40 °C to +125 °C 16
LED Current Absolute Dispersion ΔILED2 -3 3 % ILED = 50 mA, Ta = 25 °C 16
LED Current Absolute Dispersion ΔILED2 -5 5 % ILED = 50 mA, Ta = -40 °C to +125 °C 16
ISET Voltage VISET 0.9 1 1.1 V RISET = 100 kΩ 16
PWM Minimum Pulse Width tMIN 1 μs fPWM = 100 Hz to 20 kHz, ILED = 20 mA to 100 mA 16
PWM Frequency fPWM 0.1 20 kHz 16
LED Open Detection Voltage VOPEN 0.2 0.3 0.4 V VLEDn (n = 1 to 4) Sweep down 16
LED Short Detection Voltage VSHORT 4.2 4.5 4.8 V VLEDn (n = 1 to 4) Sweep up 16
LED Short Detection Latch OFF Delay Time tSHORT 70 100 130 ms RRT = 27 kΩ 16
SCP Latch OFF Delay Time tSCP 70 100 130 ms RRT = 27 kΩ 16
PWM Latch OFF Delay Time tPWM 70 100 130 ms RRT = 27 kΩ 16
ISET-GND Short Protection Impedance ISETPROT 4.7 kΩ 16
Input High Voltage VINH 2.1 V EN, SYNC, PWM, SHDETEN, LEDEN1, LEDEN2; max printed as VVREG 16
Input Low Voltage VINL 0.8 V EN, SYNC, PWM, SHDETEN, LEDEN1, LEDEN2; min printed as GND 16
Input Current IIN 15 50 100 μA VIN = 5 V (EN, SYNC, SHDETEN, PWM, LEDEN1, LEDEN2) 16
FAIL Low Voltage VOL 0.1 0.2 V IFAIL = 0.1 mA 16
LSDET Detection Voltage VLSDET 1.24 V 16
Power Supply Voltage VCC 40 V Ta = 25 °C 13
BOOT, OUTH Pin Voltage VBOOT, VOUTH 45 V Ta = 25 °C 13
SW, CS Pin Voltage VSW, VCS 40 V Ta = 25 °C 13
BOOT-SW Pin Voltage VBOOT-SW 7 V Ta = 25 °C 13
LED1 to LED4, VDISC Pin Voltage VLEDn, VVDISC 40 V Ta = 25 °C 13
PWM, SYNC, EN Pin Voltage VPWM, VSYNC, VEN -0.3 7 V Ta = 25 °C 13
VREG, OVP, FAIL1, FAIL2, SS, RT Pin Voltage VVREG, VOVP, VFAIL1, VFAIL2, VSS, VRT -0.3 7 V Printed as -0.3 to +7 < VCC; Ta = 25 °C 13
LEDEN1, LEDEN2, ISET, COMP, OUTL, SHDETEN Pin Voltage VLEDEN1, VLEDEN2, VISET, VCOMP, VOUTL, VSHDETEN -0.3 7 V Printed as -0.3 to +7 < VVREG; Ta = 25 °C 13
Maximum Junction Temperature Tjmax 150 °C 13
Storage Temperature Range Tstg -55 150 °C 13
LED Maximum Output Current ILED 120 mA Per channel 13
Thermal Resistance Junction to Ambient (HTSSOP-B28) θJA 107 °C/W 1s board (JESD51-3); 2s2p (JESD51-5, 7) is 25.10 13
Thermal Resistance Junction to Ambient (HTSSOP-B28) θJA 25.1 °C/W 2s2p board (JESD51-5, 7) 13
Junction to Top Characterization Parameter (HTSSOP-B28) ΨJT 6 °C/W 1s board 13
Junction to Top Characterization Parameter (HTSSOP-B28) ΨJT 3 °C/W 2s2p board 13

CAD (KiCad official)

  • Symbol: BD81A44EFV-ME2
  • Footprint: Package_SO:TSSOP-28-1EP_4.4x9.7mm_P0.65mm_EP2.85x6.7mm
  • 3D model: HTSSOP-28-EP (KiCad packages3D, STEP)
  • 3D model files: bd81a44efv-me2-etched.step / bd81a44efv-me2-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); bd81a44efv-me2.step / bd81a44efv-me2.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: ROHM Semicon datasheet (47 pp, sha256 af0ccb61ebed8547, retrieved 2026-10-27, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF