ISL81483

5V, Half Duplex, 250kbps Slew Rate Limited, RS-485/RS-422 Transceiver

Product Status: 量産中

OVERVIEW

These Renesas RS-485/RS-422 devices are “fractional” Unit Load (UL), BiCMOS, 5V powered, single transceivers that meet both the RS-485 and RS-422 standards for balanced communication. Unlike competitive devices, this family is specified for 10% tolerance supplies (4.5V to 5.5V).

The ISL81483 and ISL81487 present a 1/8 unit load to the RS-485 bus, which allows up to 256 transceivers on the network for large node count systems (for example, process automation, remote meter reading systems). In a remote utility meter reading system, individual (apartments for example) utility meter readings are routed to a concentrator through an RS-485 network, so the high allowed node count minimizes the number of repeaters required to network all the meters. Data for all meters is then read out from the concentrator using a single access port, or a wireless link. The slew rate limited driver on the ISL81483 reduces EMI, and minimizes reflections from improperly terminated transmission lines, or unterminated stubs in multidrop and multipoint applications. Data rates up to 250kbps are achievable with these devices.

Data rates up to 5Mbps are achievable by using the ISL81487, which features higher slew rates.

Receiver (Rx) inputs feature a “fail-safe if open” design, which ensures a logic high Rx output if Rx inputs are floating.

Driver (Tx) outputs are short-circuit protected, even for voltages exceeding the power supply voltage. Additionally, on-chip thermal shutdown circuitry disables the Tx outputs to prevent damage if power dissipation becomes excessive.

These half duplex devices multiplex the Rx inputs and Tx outputs to allow transceivers with Rx and Tx disable functions in 8 Ld packages.

KEY FEATURES

    • Fractional unit load allows up to 256 devices on the bus
    • Specified for 10% tolerance supplies
    • Class 3 ESD protection (HBM) on all pins: >7kV
    • High data rate version (ISL81487): up to 5Mbps
    • Slew rate limited version for error free data transmission (ISL81483): up to 250kbps
    • Low current shutdown mode (except ISL81487): 0.5µA
    • Low quiescent supply current:
      - ISL81483: 145µA (Max.)
      - ISL81487: 420µA (Max.)
    • -7V to +12V common-mode input voltage range
    • Three state Rx and Tx outputs
    • 30ns propagation delays, 5ns skew (ISL81487)
    • Half duplex pinouts
    • Operate from a single +5V supply (10% tolerance)
    • Current limiting and thermal shutdown for driver overload protection
    • Drop-in replacements for: MAX1483 (ISL81483); MAX1487, LMS1487 (ISL81487)
    • Pb-free plus anneal available (RoHS compliant)

PARAMETRICS

Parameters
ISL81483
Basic Information
Production Status
量産中
主な特長
Low Cost
Tx数
1
Rx数
1
バス上の許容デバイス数
256
半二重/全二重
Half
高ESD保護
No
ホットプラグ
No
データレート
0.25 Mbps
電源電圧Vcc (V) (min)
4.5
電源電圧Vcc (V) (max)
5.5
スルーレート制限
Yes
Tx/Rxイネーブル
Yes
IS イネーブル/ディセーブル
160/120 µA
SHDN ICC
0.001 µA
VLピン
No
認定レベル
Standard
電源電圧Vcc範囲 (V)
4.5 to 5.5
温度範囲
-40 to +85

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