# R5478N187CD-TR-FF

**Ricoh Elec Devices** · Battery Management ICs · SOT-23-6

R5478N187CD-TR-FF from Ricoh Elec Devices, in a SOT-23-6. 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 | DOUT | output | Output of over-discharge detection (also reflects the excess discharge-current detector), CMOS output; absolute maximum DOUT voltage range is VSS -0.3 to VDD +0.3 V. |
| 2 | V- | power_in | Pin for charger negative input; absolute maximum input voltage range is VDD -30 to VDD +0.3 V. |
| 3 | COUT | output | Output of over-charge detection, CMOS output; absolute maximum COUT output voltage range is VDD -30 to VDD +0.3 V. |
| 4 | NC | unconnected | No connection. |
| 5 | VDD | power_in | Power supply pin and substrate voltage level of the IC; absolute maximum supply voltage is -0.3 to 12 V referenced to VSS. |
| 6 | VSS | power_in | VSS pin, the ground pin for the IC and the reference for the ratings (VSS = 0 V). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Ricoh Elec Devices |
| Package | SOT-23-6 |
| Category | Power Management ICs |
| Pins | 6 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Operating input voltage | VDD1 | 1.5 |  | 5 | V | Voltage defined as VDD-VSS | 7 |
| Minimum operating voltage for 0V charging | Vst |  |  | 1.8 | V | Voltage defined as VDD-V-, VDD-VSS=0V | 7 |
| Over-charge threshold tolerance (Topt=25°C), applied to VDET1 | VDET1 | -0.025 |  | 0.025 | V | Topt=25°C, R1=330Ω, detect rising edge of supply voltage | 7 |
| Over-charge threshold tolerance (Topt=-5 to 55°C), applied to VDET1 | VDET1 | -0.03 |  | 0.03 | V | Topt=-5 to 55°C, R1=330Ω | 7 |
| Released voltage from over-charge tolerance, applied to VREL1 | VREL1 | -0.05 |  | 0.05 | V | Detect falling edge of supply voltage | 7 |
| Output delay of over-charge | tVDET1 | 0.7 | 1 | 1.3 | s | VDD=3.6V to 4.4V | 7 |
| Output delay of release from over-charge | tVREL1 | 11 | 16 | 21 | ms | VDD=4.5V to 3.6V | 7 |
| Output delay of over-discharge | tVDET2 | 14 | 20 | 26 | ms | VDD=3.6V to 2.2V | 7 |
| Output delay of release from over-discharge | tVREL2 | 0.7 | 1.2 | 1.7 | ms | VDD=3V V-=3V to 0V | 7 |
| Excess discharge-current threshold tolerance, applied to VDET3 | VDET3 | -0.015 |  | 0.015 | V | Detect rising edge of V- pin voltage | 7 |
| Output delay of excess discharge-current | tVDET3 | 8 | 12 | 16 | ms | VDD=3.0V, V-=0V to 0.4V | 7 |
| Output delay of release from excess discharge-current | tVREL3 | 0.7 | 1.2 | 1.7 | ms | VDD=3.0V, V-=3V to 0V | 7 |
| Short protection voltage | Vshort | 0.5 | 0.75 | 0.95 | V | VDD=3.0V | 7 |
| Output delay of short protection | Tshort | 230 | 300 | 500 | µs | VDD=3.0V, V-=0V to 3V | 7 |
| Reset resistance for excess discharge-current protection | Rshort | 25 | 50 | 75 | kΩ | VDD=3.6V, V-=1V | 7 |
| Delay shortening mode input voltage | VDS | -2.6 | -2 | -1.4 | V | VDD=4.4V | 7 |
| Nch ON voltage of COUT | VOL1 | 0.4 |  | 0.5 | V | Iol=50µA, VDD=4.5V | 7 |
| Pch ON voltage of COUT | VOH1 | 3.4 |  | 3.7 | V | Ioh=-50µA, VDD=3.9V | 7 |
| Nch ON voltage of DOUT | VOL2 | 0.2 |  | 0.5 | V | Iol=50µA, VDD=2.0V | 7 |
| Pch ON voltage of DOUT | VOH2 | 3.4 |  | 3.7 | V | Ioh=-50µA, VDD=3.9V | 7 |
| Supply current | IDD |  | 3 | 7 | µA | VDD=3.9V, V- =0V | 7 |
| Standby current | IS |  | 1.2 | 2 | µA | VDD=2.0V | 7 |
| Over-charge detector threshold (nominal, R5478N187CD) | VDET1 |  | 4.25 |  | V | Detect rising edge of supply voltage; R1=330Ω | 26 |
| Released voltage from over-charge (nominal, R5478N187CD) | VREL1 |  | 4.05 |  | V | Detect falling edge of supply voltage | 26 |
| Over-discharge detector threshold (nominal, R5478N187CD) | VDET2 |  | 3 |  | V | Detect falling edge of supply voltage | 26 |
| Released voltage from over-discharge (nominal, R5478N187CD) | VREL2 |  | 3.2 |  | V | Detect rising edge of supply voltage | 26 |
| Excess discharge-current threshold (nominal, R5478N187CD) | VDET3 |  | 0.15 |  | V | Detect rising edge of V- pin voltage | 26 |
| Supply voltage | VDD | -0.3 |  | 12 | V | VSS=0V | 5 |
| Output voltage, DOUT pin | VDOUT | -0.3 |  |  | V | DOUT pin; printed as VSS -0.3 to VDD +0.3 V | 5 |
| Power dissipation | PD |  |  | 150 | mW |  | 5 |
| Operating temperature range | Topt | -40 |  | 85 | °C |  | 5 |
| Storage temperature range | Tstg | -55 |  | 125 | °C |  | 5 |

## CAD (KiCad official)

- Symbol: `R5478N187CD-TR-FF`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files: `r5478n187cd-tr-ff-etched.step` / `r5478n187cd-tr-ff-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `r5478n187cd-tr-ff.step` / `r5478n187cd-tr-ff.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Ricoh Elec Devices datasheet](docs/r5478n187cd-tr-ff-datasheet.pdf) (27 pp, sha256 `e02e7c3c39eec61e`, retrieved 2026-10-28, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-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](docs/r5478n187cd-tr-ff-datasheet.pdf)