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BU91797MUF-ME2
Public Made by Adomby adom
ROHM Semicon LCD Drivers, VQFN-48-EP(7x7). Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
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Datasheet
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README
markdownBU91797MUF-ME2
ROHM Semicon · LCD Drivers · VQFN-48-EP(7x7)
BU91797MUF-ME2 from ROHM Semicon, in a VQFN-48-EP(7x7). 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 | SEG1 | output | Segment output for LCD driving; leave open when unused. |
| 2 | SEG2 | output | Segment output for LCD driving; leave open when unused. |
| 3 | SEG3 | output | Segment output for LCD driving; leave open when unused. |
| 4 | SEG4 | output | Segment output for LCD driving; leave open when unused. |
| 5 | SEG5 | output | Segment output for LCD driving; leave open when unused. |
| 6 | SEG6 | output | Segment output for LCD driving; leave open when unused. |
| 7 | SEG7 | output | Segment output for LCD driving; leave open when unused. |
| 8 | SEG8 | output | Segment output for LCD driving; leave open when unused. |
| 9 | SEG9 | output | Segment output for LCD driving; leave open when unused. |
| 10 | SEG10 | output | Segment output for LCD driving; leave open when unused. |
| 11 | SEG11 | output | Segment output for LCD driving; leave open when unused. |
| 12 | SEG12 | output | Segment output for LCD driving; leave open when unused. |
| 13 | SEG13 | output | Segment output for LCD driving; leave open when unused. |
| 14 | SEG14 | output | Segment output for LCD driving; leave open when unused. |
| 15 | SEG15 | output | Segment output for LCD driving; leave open when unused. |
| 16 | SEG16 | output | Segment output for LCD driving; leave open when unused. |
| 17 | SEG17 | output | Segment output for LCD driving; leave open when unused. |
| 18 | SEG18 | output | Segment output for LCD driving; leave open when unused. |
| 19 | SEG19 | output | Segment output for LCD driving; leave open when unused. |
| 20 | SEG20 | output | Segment output for LCD driving; leave open when unused. |
| 21 | SEG21 | output | Segment output for LCD driving; leave open when unused. |
| 22 | SEG22 | output | Segment output for LCD driving; leave open when unused. |
| 23 | SEG23 | output | Segment output for LCD driving; leave open when unused. |
| 24 | SEG24 | output | Segment output for LCD driving; leave open when unused. |
| 25 | SEG25 | output | Segment output for LCD driving; leave open when unused. |
| 26 | SEG26 | output | Segment output for LCD driving; leave open when unused. |
| 27 | SEG27 | output | Segment output for LCD driving; leave open when unused. |
| 28 | SEG28 | output | Segment output for LCD driving; leave open when unused. |
| 29 | SEG29 | output | Segment output for LCD driving; leave open when unused. |
| 30 | SEG30 | output | Segment output for LCD driving; leave open when unused. |
| 31 | SEG31 | output | Segment output for LCD driving; leave open when unused. |
| 32 | SEG32 | output | Segment output for LCD driving; leave open when unused. |
| 33 | SEG33 | output | Segment output for LCD driving; leave open when unused. |
| 34 | SEG34 | output | Segment output for LCD driving; leave open when unused. |
| 35 | SEG35 | output | Segment output for LCD driving; leave open when unused. |
| 36 | COM0 | output | Common output for LCD driving; leave open when unused. |
| 37 | COM1 | output | Common output for LCD driving; leave open when unused. |
| 38 | COM2 | output | Common output for LCD driving; leave open when unused. |
| 39 | COM3 | output | Common output for LCD driving; leave open when unused. |
| 40 | VLCD | power_in | Power supply for LCD driving, 0V to VDD-2.4V (VDD-VLCD must be at least 2.4V). |
| 41 | VDD | power_in | Power supply, 2.5V to 6.0V (absolute maximum 7.0V); place a capacitor above 0.1µF between VDD and VSS. |
| 42 | VSS | power_in | Ground. |
| 43 | TEST1 | input | Test input for ROHM use only; must be connected to VSS. |
| 44 | OSCIN | input | External clock input, selectable against the internal clock by command; must be connected to VSS when using the internal oscillator. |
| 45 | SCL | input | Serial clock terminal of the 2-wire serial interface. |
| 46 | SDA | bidirectional | Serial data in-out terminal of the 2-wire serial interface, with VOL of 0.4V max at 3mA load. |
| 47 | TEST2 | input | POR enable setting: VDD disables POR (software reset then required), VSS enables POR; connect to VSS when unused. |
| 48 | SEG0 | output | Segment output for LCD driving; leave open when unused. |
| 49 | EXT-PAD | passive | Exposed substrate pad on the bottom of the package for heat radiation; contact it to the board and supply VSS level or leave open. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | ROHM Semicon |
| Package | VQFN-48-EP(7x7) |
| Category | Nixie Tube Driver/LED Driver |
| Pins | 49 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Maximum Voltage1 (Power Supply) | VDD | -0.5 | 7 | V | VSS=0V | 4 | |
| Maximum Voltage2 (LCD Drive Voltage) | VLCD | -0.5 | V | -0.5 to VDD; VSS=0V | 4 | ||
| Power Dissipation BU91797MUF-M | Pd | 0.93 | W | Derate by 9.3mW/°C above Ta=+25°C, ROHM standard board | 4 | ||
| Input Voltage Range | VIN | -0.5 | V | -0.5 to VDD+0.5 | 4 | ||
| Operational Temperature Range | Topr | -40 | 105 | °C | 4 | ||
| Storage Temperature Range | Tstg | -55 | 125 | °C | 4 | ||
| Power Supply Voltage1 | VDD | 2.5 | 6 | V | Ta=-40°C to +105°C, VSS=0V | 4 | |
| Power Supply Voltage2 (LCD Drive Voltage) | VLCD | 0 | V | Max is VDD-2.4V; VDD-VLCD ≥ 2.4V | 4 | ||
| "H" Level Input Current | IIH | 1 | µA | SDA, SCL, OSCIN(Note 3), TEST2 | 4 | ||
| "L" Level Input Current | IIL | -1 | µA | SDA, SCL, OSCIN, TEST2 | 4 | ||
| SDA "L" Level Output Voltage | VOL_SDA | 0 | 0.4 | V | Iload = 3mA | 4 | |
| VLCD Supply Voltage | VLCD | 0 | V | Max is VDD-2.4V; VDD-VLCD≥2.4V | 4 | ||
| Standby Current | IDD1 | 5 | µA | Display off, Oscillation off | 4 | ||
| Power Consumption | IDD2 | 12.5 | 30 | µA | VDD=3.3V, VLCD=0V, Ta=+25°C, Power save mode1, FR=71Hz, 1/3 bias, Frame inverse | 4 | |
| Frame Frequency1 | fCLK1 | 56 | 80 | 112 | Hz | FR = 80Hz setting, VDD=2.5V to 6.0V, Ta=-40°C to +105°C | 5 |
| Frame Frequency2 | fCLK2 | 70 | 80 | 90 | Hz | FR = 80Hz setting, VDD=3.3V, Ta=+25°C | 5 |
| Frame Frequency3 | fCLK3 | 77.5 | 87.5 | 97.5 | Hz | FR = 80Hz setting, VDD=5.0V, Ta=+25°C | 5 |
| Frame Frequency4 | fCLK4 | 67.5 | 87.5 | 108 | Hz | FR = 80Hz setting, VDD=5.0V, Ta=-40°C to +105°C | 5 |
| External Clock Rise Time | tr | 0.3 | µs | External clock mode (OSCIN) | 5 | ||
| External Clock Fall Time | tf | 0.3 | µs | External clock mode (OSCIN) | 5 | ||
| External Frequency | fEXCLK | 15 | 300 | kHz | External clock mode (OSCIN) | 5 | |
| External Clock Duty | tDTY | 30 | 50 | 70 | % | External clock mode (OSCIN) | 5 |
| Input Rise Time | tr | 0.3 | µs | 6 | |||
| Input Fall Time | tf | 0.3 | µs | 6 | |||
| SCL Cycle Time | tSCYC | 2.5 | µs | 6 | |||
| "H" SCL Pulse Width | tSHW | 0.6 | µs | 6 | |||
| "L" SCL Pulse Width | tSLW | 1.3 | µs | 6 | |||
| SDA Setup Time | tSDS | 100 | ns | 6 | |||
| SDA Hold Time | tSDH | 100 | ns | 6 | |||
| Buss Free Time | tBUF | 1.3 | µs | 6 | |||
| START Condition Hold Time | tHD;STA | 0.6 | µs | 6 | |||
| START Condition Setup Time | tSU;STA | 0.6 | µs | 6 | |||
| STOP Condition Setup Time | tSU;STO | 0.6 | µs | 6 | |||
| LCD Driver On Resistance SEG | RON | 3 | kΩ | SEG, Iload=±10µA | 4 | ||
| LCD Driver On Resistance COM | RON | 3 | kΩ | COM, Iload=±10µA | 4 |
CAD (KiCad official)
- Symbol:
BU91797MUF-ME2 - Footprint:
Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.15x5.15mm - 3D model: VQFN-48-EP(7x7) (KiCad packages3D, STEP)
- 3D model files:
bu91797muf-me2-etched.step/bu91797muf-me2-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bu91797muf-me2.step/bu91797muf-me2.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: ROHM Semicon datasheet (30 pp, sha256
e7404bbda6983c5c, retrieved 2026-10-27, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text), consensusclaude-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).