MAX4823 Maxim, MAX4823 Datasheet

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MAX4823

Manufacturer Part Number
MAX4823
Description
The MAX4822–MAX4825 8-channel relay drivers offer built-in kickback protection and drive +3V/+5V nonlatching or dual-coil-latching relays
Manufacturer
Maxim
Datasheet
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 2.7
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.
19-3789; Rev 0; 8/05
SPI is a trademark of Motorola, Inc.
QSPI is a trademark of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
ATE Equipment
DSL Redundancy Protection (ADSL/VDSL/HDSL)
T1/E1 Redundancy Protection
T3/E3 Redundancy Protection
Industrial Equipment
Test Equipment (Oscilloscopes, Spectrum
Analyzers)
+3.3V/+5V, 8-Channel Relay Drivers with Fast
________________________________________________________________ Maxim Integrated Products
General Description
Recovery Time and Power-Save Mode
Applications
(typ) on-resistance
♦ Built-In Zener Kickback Protection for Fast
♦ Programmable Power-Save Mode Reduces Relay
♦ 10MHz SPI-/QSPI-/MICROWIRE-Compatible Serial
♦ Eight Independent Output Channels
♦ Drive +3V and +5V Relays
♦ Guaranteed 70mA (min) Coil Drive Current
♦ Guaranteed 5 (max) R
♦ SET / RESET Functions to Turn On/Off All
♦ 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
*For maximum heat dissipation, packages have an exposed
pad (EP) on the bottom. Solder exposed pad to GND.
Pin Configurations appear at end of data sheet.
MAX4822ETP
MAX4823ETP
MAX4824ETP
MAX4825ETP
Recovery
Power Consumption (MAX4822/MAX4824)
Interface
Outputs Simultaneously
PART
MAX4822
MAX4823
MAX4824
MAX4825
PART
-40°C to +85°C 20 TQFN-EP*
-40°C to +85°C 20 TQFN-EP*
-40°C to +85°C 20 TQFN-EP*
-40°C to +85°C 20 TQFN-EP*
TEMP RANGE
Ordering Information
INTERFACE
Parallel
Parallel
Serial
Serial
ON
PIN-
PACKAGE
Selector Guide
POWER SAVE
Features
PACKAGE
Yes
Yes
No
No
T2044-3
T2044-3
T2044-3
T2044-3
CODE
1

Related parts for MAX4823

MAX4823 Summary of contents

Page 1

... 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 ...

Page 2

... Continuous OUT_ Current (single output turned on) ........300mA Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability ...

Page 3

... Power-Save On V (MAX4822) OUT_ Drive Voltage, V Power-Save On (MAX4824) OUT_ On-Resistance OUT_ Off-Leakage Current Zener Clamping Voltage V SPI TIMING (MAX4822/MAX4823) Turn-On Time (OUT_) Turn-Off Time (OUT_) SCLK Frequency Cycle Time Fall-to-SCLK Rise Setup CS Rise-to-SCLK Hold SCLK High Time SCLK Low Time ...

Page 4

Relay Drivers with Fast Recovery Time and Power-Save Mode ELECTRICAL CHARACTERISTICS (continued +2.7V to +5.5V -40°C to +85°C, unless otherwise noted. Typical values are noted.) (Note 1) PARAMETER SYMBOL Data ...

Page 5

Relay Drivers with Fast Recovery Time and Power-Save Mode (V = 3.3V +25°C, unless otherwise noted QUIESCENT SUPPLY CURRENT vs. SUPPLY VOLTAGE 180 ALL CHANNELS OFF 175 170 165 160 155 150 145 140 ...

Page 6

Relay Drivers with Fast Recovery Time and Power-Save Mode (V = 3.3V +25°C, unless otherwise noted OUT_ TURN-ON DELAY TIME vs. SUPPLY VOLTAGE 140 120 100 2.3 2.7 3.1 3.5 ...

Page 7

... Serial Data Input Serial Clock Input Serial Data Output. DOUT is the output of the shift register. DOUT can be used to daisy- chain multiple MAX4822/MAX4823 devices. The data at DOUT appears synchronous to SCLK’s falling edge. No Connection. Not internally connected. Ground Open-Drain Output 8 ...

Page 8

... OUT6 12 12 OUT5 8 _______________________________________________________________________________________ MAX4822/MAX4823 Pin Description (continued) FUNCTION Input Supply Voltage. Bypass V to GND with a 0.1µF capacitor. CC Set Input. Drive SET low to set all latches and registers high (all outputs are low impedance). SET overrides all parallel and serial control inputs. RESET overrides SET under all conditions ...

Page 9

... Serial Interface (MAX4822/MAX4823) Depending on the MAX4822/MAX4823 device, the serial interface can be controlled by either 8- or 16-bit words as depicted in Figures 1 and 2. The MAX4823 does not support power-save mode, so the serial interface con- sists of an 8-bit-only shift register for faster control. The MAX4822 consists of a 16-bit shift register and par- allel latch controlled by SCLK and CS ...

Page 10

... DOUT synchronously with SCLK’s falling edge and is identical to the data at DIN delayed by eight clock cycles for the MAX4823 clock cycles for the MAX4822. When shifting the input data the first input bit in and out of the shift register for the MAX4822 device ...

Page 11

... CS is low is greater or less than 16, the shift regis- ter contains only the last 16 bits, regardless of when they were entered. For the MAX4823, if the number of data bits entered while CS is low is greater or less than 8, the shift register contains only the last 8 data bits, regardless of when they were entered ...

Page 12

... Figure 8). During operation, a stream of serial data is shifted through the MAX4822/ MAX4823 devices in series. When CS goes high, all outputs update simultaneously. The MAX4822/MAX4823 can also be used in a slave configuration that allows individual addressing of devices. Connect all the DIN inputs together, and use 12 ...

Page 13

... MOSFET low for the duration of a write cycle to the SPI chain, plus some delay time to allow the relays to close. ______________________________________________________________________________________ is given by the fol 20ms, then the SCLK DIN supply CC Figure 6. 3-Wire Serial-Interface Operation for the MAX4823 in ON, according to the fol depends on the PS ...

Page 14

... The Zener configuration significantly reduces the recovery time (time it takes to turn off the relay) when compared to protection configurations with just one diode across the coil 0 DIN DOUT MAX4823 OUT1 SCLK SCLK OUT8 CS GND PGND ...

Page 15

Relay Drivers with Fast Recovery Time and Power-Save Mode DIN DIN MAX4822 PSAVE SCLK SCLK N CS Figure 10. Daisy-Chaining MAX4822s with a PSAVE Connected to an n-Channel MOSFET ______________________________________________________________________________________ 0.1 ...

Page 16

... Relay Drivers with Fast Recovery Time and Power-Save Mode MAX4822/MAX4823 Functional Diagram (Serial Interface MAX4822 MAX4823 RESET SET DIN SHIFT REGISTER DOUT SCLK CS PSAVE GND MAX4822 ONLY 16 ______________________________________________________________________________________ POWER- ON RESET PSAVE POWER-SAVE CONFIGURATION REGISTER ON1 CONTROL ON2 REGISTER ...

Page 17

Relay Drivers with Fast Recovery Time and Power-Save Mode MAX4824/MAX4825 Functional Diagram (Parallel Interface MAX4824 MAX4825 RESET SET LVL A2 4-TO-8 DECODER PSAVE GND MAX4824 ONLY ______________________________________________________________________________________ PSAVEON/OFF ON1 CONTROL ON2 REGISTER ON3 ...

Page 18

... OUT3 RESET 1 14 OUT4 PSAVE DIN 3 12 OUT5 SCLK 4 11 OUT6 DOUT 5 RESET 1 15 OUT3 14 OUT4 PSAVE LVL 3 12 OUT5 OUT6 A1 5 Pin Configurations 15 OUT3 14 OUT4 13 N.C. MAX4823 12 OUT5 11 OUT6 THIN QFN 15 OUT3 14 OUT4 13 N.C. MAX4825 12 OUT5 11 OUT6 THIN QFN ...

Page 19

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19 © ...

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