2557

Plating :
Thread Size :
Length :
Material : Nylon
Outside Diameter : 25.8 mm
Type : Louvered Plugs


Features:

  300 mA Output Current per Channel
  Independent Over-Current Protection &Thermal Limiting for Each Driver
  Output Voltage to 60 V
  Output SOA Protection
  Fault-Detection Circuitry for Open or Shorted Load
  Low Quiescent Current Sleep Mode
  Integral Output Flyback/Clamp Diodes
  TTL- and 5 V CMOS-Compatible Inputs


Pinout




Specifications

Output Voltage, V_O .............................. 60 V
Over-Current Protected Output Voltage,
    V_O .....................................................32 V
Output Current, I_O ......................... 500 mA*
FAULT Output Voltage, V_FLT ............. ....60 V
Logic Supply Voltage, V_CC ....................7.0 V
Input Voltage, V_I or V_OE .......................7.0 V
Package Power Dissipation,
    P_D ........................................... See Graph
Operating Temperature Range, T_A
   Suffix 'S-' ........................-20 to +85
   Suffix 'E-' ...................... .-40 to +85
   Suffix 'K-' ......................-40 to +125
Junction Temperature,
   T_J ...................................................+150*
Storage Temperature Range,
   T_S ................................... ..-55 to +150


Description

The A2557xB, A2557xEB, and A2557xLB have been specifically designed to provide cost-effective solutions to relay-driving applications with up to 300 mA drive current per channel. They may also be used for driving incandescent lamps in applications where turn-on time is not a concern. Each of the four outputs will sink 300 mA in the on state. The outputs of  A2557xB, A2557xEB, and A2557xLB  have a minimum breakdown voltage of 60 V and a sustaining voltage of 40 V. A low-power Sleep Mode is activated with either ENABLE low or all inputs low. In this mode, the supply current drops to below 100 A.

Over-current protection for each channel has been designed into these devices and is activated at a nominal 500 mA.  A2557xB, A2557xEB, and A2557xLB protects each output from short circuits with supply voltages up to 32 V. When an output experiences a short circuit, the output current is limited at the 500 mA current clamp. In addition, foldback circuitry decreases the current limit if an excessive voltage is present across the output and assists in keeping the device within its SOA (safe operating area). An exclusive-OR circuit compares the input and output state of each driver. If either a short or open load condition is detected, a single FAULT output is turned on (active low). Similar devices, for operation  to 1.3 A, are available as the UDx2547B/EB.

Continuous or multiple overload conditions causing the channel temperature to reach approximately 165°C will result in an additional linear decrease in the output current of the affected driver. If the fault condition of  A2557xB, A2557xEB, and A2557xLB is corrected, the output stage will return to its normal saturated condition.

The first character of the part number suffix determines  A2557xB, A2557xEB, and A2557xLB operating temperature range. Suffix 'S-' is the standard -20°C to +85°C; suffix 'E-' is -40°C to +85°C; suffix 'K-' is for the industrial temperature range of -40°C to +125°C. Package suffix '-B' devices are 16-pin power DIPs; suffix '-EB' devices are 28-lead power PLCCs; and suffix '-LB' are 16- lead power wide-body SOICs for surface-mount applications. All packages of A2557xB, A2557xEB, and A2557xLB are of batwing construction to provide for maximum package power dissipation.