特長
- IEC 61000-4-2 ESD protection on RS-485 I/O pins
- Air-gap discharge: ±15kV
- Contact discharge: ±8kV
- HBM Class 3B ESD level on all other pins: ±9kV
- IEC 61000-4-4 Electrical Fast Transient (EFT) protection on RS-485 I/O pins: ±5kV
- Full fail-safe (open, short, terminated/floating) receivers
- Hot plug - Tx and Rx outputs remain three-state during power-up
- True 1/8 unit load allows up to 256 devices on the bus
- Single 3.3V or 5V supply
- Data rate: Up to 0.25Mbps
- Low quiescent supply current: 400μA (Typ.)
- Low shutdown (SHDN) current: < 0.6μA (Typ.)
- -7V to +12V common-mode input/output voltage range
- Half-duplex operation
説明
The RRA48315 is a ±15kV IEC 61000-4-2 ESD-protected, 3.3V to 5V powered single transceiver that meets both the RS-485 and RS-422 standards for balanced communication. This device has very low bus currents (+125μA/-100μA), so it presents a true 1/8 unit load to the RS-485 bus. This allows up to 256 transceivers on the network without violating the RS-485 specification's 32-unit load maximum, and without using repeaters. For example, in a remote utility meter reading system, individual meter readings are routed to a concentrator using an RS-485 network, so the high allowed node count minimizes the number of repeaters required.
Hot plug circuitry ensures that the transmitter (Tx) and receiver (Rx) outputs remain in a high-impedance state while the power supply stabilizes.
Rx inputs feature a full fail-safe design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or terminated but undriven.
The RRA48315 uses slew rate limited drivers, which reduce EMI and minimize reflections from improperly terminated transmission lines or unterminated stubs in multidrop and multipoint applications. Slew rate limited versions also include receiver input filtering to enhance noise immunity in the presence of slow input signals.
The RRA48315 is configured for half-duplex applications.
パラメータ
| 属性 | 値 |
|---|---|
| Vcc (V) | 3.0-5.5 |
| Tx/Rx per Port | 1/1 |
| Half/Full Duplex | Half |
| Devices Allowed on Bus | 256 |
| ESD Standard | IEC 61000-4-2 |
| Data Rate RS-485/RS-232 | 0.25 |
| Temp. Range (°C) | -40 to +105°C |
製品比較
| RRA48315 | RRA48316 | RRA48355 | RRA48325 | |
| Half/Full Duplex | Half | Full | Half | Half |
| Data Rate RS-485/RS-232 | 0.25 | 0.25 | 20 | 1 |
| ESD Standard | IEC 61000-4-2 | IEC 61000-4-2 | IEC 61000-4-2 | IEC 61000-4-2 |
| Pkg. Type | MSOP, SOICN | MSOP, SOICN | MSOP, SOICN | MSOP, SOICN |
| Lead Count (#) | 8 | 10, 14 | 8 | 8 |
| Pkg. Dimensions (mm) | 3.0 x 3.0 x 0.00, 4.9 x 3.9 x 0.00 | 3.0 x 3.0 x 0.85, 8.7 x 3.9 x 0.00 | 3.0 x 3.0 x 0.00, 4.9 x 3.9 x 0.00 | 3.0 x 3.0 x 0.00, 4.9 x 3.9 x 0.00 |
アプリケーション
- Automated utility meter reading systems
- High node count systems
- Field bus networks
- Security camera networks
- Building environmental control/lighting systems
- Industrial/Process control networks
