MAX4822 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – +3.3V/+5V, 8-Channel Relay Drivers with Fast Recovery Time and Power-Save Mode

19-3789; Rev 0; 8/05
+3.3V/+5V, 8-Channel Relay Drivers with Fast
Recovery Time and Power-Save Mode
General Description
Features
The MAX4822–MAX4825 8-channel relay drivers offer
built-in kickback protection and drive +3V/+5V non-
latching or dual-coil-latching relays. Each independent
open-drain output features a 2.7Ω (typ) on-resistance
and is guaranteed to sink 70mA (min) of load current.
These devices consume less than 300µA (max) quies-
cent current and have 1µA output off-leakage current.
A Zener-kickback-protection circuit significantly
reduces recovery time in applications where switching
speed is critical.
The MAX4822/MAX4824 feature a unique power-save
mode where the relay current, after activation, can be
reduced to a level just above the relay hold-current
threshold. This mode keeps the relay activated while
significantly reducing the power consumption.
The MAX4822/MAX4823 feature a 10MHz SPI™-/
QSPI™-/MICROWIRE™-compatible serial interface.
Input data is shifted into a shift register and latched to
the outputs when CS transitions from low to high. Each
data bit in the shift register corresponds to a specific
output, allowing independent control of all outputs.
The MAX4824/MAX4825 feature a 4-bit parallel-input
interface. The first 3 bits (A0, A1, A2) determine the out-
put address, and the fourth bit (LVL) determines whether
the selected output is switched on or off. Data is latched
to the outputs when CS transitions from low to high.
The MAX4822–MAX4825 feature separate set and reset
functions, allowing turn-on or turn-off of all outputs
simultaneously with a single control line. Built-in hys-
teresis (Schmidt trigger) on all digital inputs allows
these devices to be used with slow-rising and falling
signals, such as those from optocouplers or RC power-
up initialization circuits. The MAX4822–MAX4825 are
available in space-saving 4mm x 4mm, 20-pin thin QFN
packages. They are specified over the -40°C to +85°C
extended temperature range.
♦ Built-In Zener Kickback Protection for Fast
Recovery
♦ Programmable Power-Save Mode Reduces Relay
Power Consumption (MAX4822/MAX4824)
♦ 10MHz SPI-/QSPI-/MICROWIRE-Compatible Serial
Interface
♦ Eight Independent Output Channels
♦ Drive +3V and +5V Relays
♦ Guaranteed 70mA (min) Coil Drive Current
♦ Guaranteed 5Ω (max) R_ON
♦ SET / RESET Functions to Turn On/Off All
Outputs Simultaneously
♦ Serial Digital Output for Daisy Chaining
♦ Optional Parallel Interface (MAX4824/MAX4825)
♦ Low 300µA (max) Quiescent Supply Current
♦ Space-Saving, 4mm x 4mm, 20-Pin TQFN Package
Ordering Information
PART
TEMP RANGE ^PIN-
PACKAGE
PACKAGE
CODE
MAX4822ETP -40°C to +85°C 20 TQFN-EP* T2044-3
MAX4823ETP -40°C to +85°C 20 TQFN-EP* T2044-3
MAX4824ETP -40°C to +85°C 20 TQFN-EP* T2044-3
MAX4825ETP -40°C to +85°C 20 TQFN-EP* T2044-3
*For maximum heat dissipation, packages have an exposed
pad (EP) on the bottom. Solder exposed pad to GND.
Applications
ATE Equipment
DSL Redundancy Protection (ADSL/VDSL/HDSL)
T1/E1 Redundancy Protection
T3/E3 Redundancy Protection
Industrial Equipment
Test Equipment (Oscilloscopes, Spectrum
Analyzers)
SPI is a trademark of Motorola, Inc.
QSPI is a trademark of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Selector Guide
PART
MAX4822
MAX4823
MAX4824
MAX4825
INTERFACE
Serial
Serial
Parallel
Parallel
POWER SAVE
Yes
No
Yes
No
Pin Configurations appear at end of data sheet.
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