A2550 Datasheet, PDF (1/15 Pages) Allegro MicroSystems – Relay Driver with 5 V Regulator

A2550
Relay Driver with 5 V Regulator
for Automotive Applications
Features and Benefits
▪ Three independent low-side DMOS output drivers
▪ Short-circuit protection of drivers
▪ Eliminates need for flyback diodes on relays
▪ Thermal shutdown
▪ Separate precision 5 V regulator (2%)
▪ Current clamp on 5 V regulator
▪ 16-pin TSSOP package with exposed thermal pad
▪ Programmable reset (NPOR) delay time
▪ Programmable watchdog
▪ Automotive voltage and temperature ranges
▪ Active clamps for automotive load dump specifications
▪ Lead (Pb) free
Package: 16 pin TSSOP (suffix LP) with
exposed pad
Description
Large numbers of relay-based applications require the use of a
microprocessor which implements complex system control. In
these systems, there is the need for microprocessor logic supply
voltage, power-on reset circuitry, and watchdog capabilities. The
Allegro^® A2550 combines the functions of voltage regulator,
watchdog, and reset, as well as three low-side DMOS relay
driver outputs. Primarily targeted at automotive applications,
this IC is designed to provide robust performance over extended
voltage and temperature ranges.
Three low-side DMOS drivers can drive inductive loads, such
as relay coils. Each driver integrates rugged voltage clamps
which survive automotive load dump pulses up to 48 V. The
40 V rating on VBB also ensures adequate survival in harsh
automotive environments.
A 5 V linear regulator provides 40 mA of output current, with
a tolerance of 2% over the operating temperature range. To
enhance the usefulness of the IC in automotive applications,
the 5 V regulator output, as well as the three low-side driver
outputs are protected against overcurrent conditions.
Approximate Scale
Continued on the next page…
Typical Application
System
Logic
1
16
IN1
OUT1
2
15
IN2
OUT2
3
IN3
A2550 OUT3 ¹⁴
4
13
LGND
PGND
5
12
NPOR
CWD
6
11
WDI
CPOR
7
10
EN
ENBAT
8
9
VREG5
VBB
0.47 μF
X7R
Relays or other
inductive loads
2550-DS, Rev. 4