# HT487EARZ

**HTCSEMI** · RS-485/RS-422 ICs · SOP-8

HT487EARZ from HTCSEMI, in a SOP-8. 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 | RO | output | Receiver output, three-state; high if A-B ≥ +0.2V or the input is open, low if A-B ≤ -0.2V, high-impedance when RE is high (VOH 3.5V min at -4mA, VOL 0.4V max at 4mA). |
| 2 | RE | input | Active-low receiver output enable; low enables RO, high puts RO in high impedance (VIH 2.0V min, VIL 0.8V max). |
| 3 | DE | input | Driver output enable; high enables the driver outputs A and B, low puts them in high impedance (VIH 2.0V min, VIL 0.8V max). |
| 4 | DI | input | Driver input; with DE high a low on DI forces the non-inverting output low and a high forces it high (VIH 2.0V min, VIL 0.8V max). |
| 5 | GND | power_in | Ground, reference for all voltages. |
| 6 | A | bidirectional | Noninverting receiver input and noninverting driver output on the RS-485/RS-422 bus, with -7V to +12V common-mode range and ±15kV HBM ESD protection. |
| 7 | B | bidirectional | Inverting receiver input and inverting driver output on the RS-485/RS-422 bus, with -7V to +12V common-mode range and ±15kV HBM ESD protection. |
| 8 | VCC | power_in | Positive supply, single 5V ±5% operation (absolute maximum 12V). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HTCSEMI |
| Package | SOP-8 |
| Category | Interface ICs |
| Pins | 8 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Supply Voltage | VCC |  |  | 12 | V |  | 1 |
| Driver Output Voltage (A, B) |  | -8 |  | 12.5 | V |  | 1 |
| Receiver Input Voltage (A, B) |  | -8 |  | 12.5 | V |  | 1 |
| Control Input Voltage |  | -0.5 |  |  | V | upper limit printed as (VCC + 0.5V) | 1 |
| Driver Input Voltage | DI | -0.5 |  |  | V | upper limit printed as (VCC+ 0.5V) | 1 |
| Receiver Output Voltage | RO | -0.5 |  |  | V | upper limit printed as (VCC+0.5V) | 1 |
| Operating Temperature Range |  | -40 |  | 85 | °C |  | 1 |
| Storage Temperature Range |  | -65 |  | 160 | °C | as printed | 1 |
| Lead Temperature (soldering) |  |  |  | 300 | °C | soldering, 10 sec | 1 |
| Continuous Power Dissipation, 8-Pin SO |  |  |  | 471 | mW | 8-Pin SO (derate 5.88mW/°C) | 1 |
| Input High Voltage | VIH | 2 |  |  | V | DE, DI, RE | 2 |
| Input Low Voltage | VIL |  |  | 0.8 | V | DE, DI, RE | 2 |
| Input Current | IIN1 | -2 |  | 2 | µA | DE, DI, RE | 2 |
| Input Current (A, B) | IIN2 |  |  | 1 | mA | DE = 0V; VIN = 12V | 2 |
| Input Current (A, B) | IIN2 | -0.8 |  |  | mA | VCC = 0V or 5.25V, VIN = -7V | 2 |
| Receiver Differential Threshold Voltage | VTH | -0.2 |  | 0.2 | V | -7V ≤ VCM ≤12V | 2 |
| Receiver Output High Voltage | VOH | 3.5 |  |  | V | IO = -4mA, VID = 200mV | 2 |
| Receiver Output Low Voltage | VOL |  |  | 0.4 | V | IO = 4mA, VID = -200mV | 2 |
| Three-State (high impedance) Output Current at Receiver | IOZR | -1 |  | 1 | µA | 0.4V ≤ VO ≤ 2.4V | 2 |
| Differential Driver Output (with load) | VOD2 | 2 |  |  | V | R = 50Ω (RS-422) | 2 |
| Differential Driver Output (with load) | VOD2 | 1.5 |  | 5 | V | R = 27Ω (RS-485), Figure 4 | 2 |
| No-Load Supply Current (Note 3) | ICC |  | 500 | 900 | µA | DE = VCC | 2 |
| No-Load Supply Current (Note 3) | ICC |  | 300 | 500 | µA | RE = 0V or VCC; DE = 0V | 2 |
| Driver Short-Circuit Current, VO = High | IOSD1 |  | 35 | 250 | mA | -7V ≤ VO ≤ 12V (Note 4) | 2 |
| Driver Short-Circuit Current, VO = Low | IOSD2 |  | 35 | 250 | mA | -7V ≤ VO ≤12V (Note 4) | 2 |
| Receiver Short-Circuit Current | IOSR |  | 7 | 95 | mA | 0V ≤ VO ≤ VCC | 2 |
| Driver Input to Output (low-to-high) | tPLH | 10 | 30 | 60 | ns | RDIFF = 54, CL1 = CL2 = 100pF | 3 |
| Driver Input to Output (high-to-low) | tPHL | 10 | 30 | 60 | ns | CL1 = CL2 = 100pF | 3 |
| Driver Output Skew to Output | tSKEW |  | 5 | 10 | ns | RDIFF = 54, CL1 = CL2 = 100pF | 3 |
| Driver Enable to Output High | tZH |  | 40 | 70 | ns | CL= 100pF, S2 closed | 3 |
| Driver Enable to Output Low | tZL |  | 40 | 70 | ns | CL= 100pF, S1 closed | 3 |
| Driver Disable Time from Low | tLZ |  | 40 | 70 | ns | CL= 15pF, S1 closed | 3 |
| Driver Disable Time from High | tHZ |  | 40 | 70 | ns | CL= 15pF, S2 closed | 3 |
| Receiver Enable to Output Low | tZL |  | 20 | 50 | ns | CRL = 15pF, S1 closed | 3 |
| Receiver Enable to Output High | tZH |  | 20 | 50 | ns | CRL = 15pF, S2 closed | 3 |
| Receiver Disable Time from Low | tLZ |  | 20 | 50 | ns | CRL = 15pF, S1 closed | 3 |
| Receiver Disable Time from High | tHZ |  | 20 | 50 | ns | CRL = 15pF, S2 closed | 3 |
| Maximum Data Rate | fMAX |  |  | 2.5 | Mbps |  | 3 |

## CAD (KiCad official)

- Symbol: `HT487EARZ`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `ht487earz-etched.step` / `ht487earz-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ht487earz.step` / `ht487earz.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HTCSEMI datasheet](docs/ht487earz-datasheet.pdf) (5 pp, sha256 `4ab9cb1dbb1da130`, retrieved 2026-11-05, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/ht487earz-datasheet.pdf)