MAX4820, MAX4821 +3.3V/+5V, 8-Channel, Cascadable Relay Drivers with Serial/Parallel Interface

Description

The MAX4820/MAX4821 8-channel relay drivers offer built-in kickback protection and drive +3.3V/+5V nonlatching or dual-coil-latching relays. These devices are especially useful when driving +3V relays. Each independent open-drain output features a 2Ω on-resistance and is guaranteed to sink 70mA (min) of load current. Both devices consume less than 50µA (max) quiescent current and have 1µA output off-leakage current.

The MAX4820 features an SPI™-/QSPI™-/MICROWIRE™-compatible serial interface. Input data is shifted into an 8-bit shift register and latched to the outputs when CS-bar transitions from low to high. Each data bit in the shift register corresponds to a specific output, allowing independent control of all outputs.

The MAX4821 features a 4-bit (A0, A1, A2, LVL) parallel-input interface. The first three bits (A0, A1, A2) determine the output address, and the fourth bit (LVL) determines whether the selected output is switched on or off. Data is latched to the outputs when CS-bar transitions from low to high.

Both devices feature separate set and reset functions that allow the user to turn on or turn off all outputs simultaneously with a single control line. Built-in hysteresis (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 MAX4820/MAX4821 are available in 20-pin TSSOP and space-saving 20-pin thin QFN packages.

Key Features

Applications/Uses

	8 Independent Output Channels
	Built-In Inductive Kickback Protection
	Drive +3V and +5V Relays
	Guaranteed 70mA (min) Coil Drive Current
	SET-bar Function to Turn On All Outputs Simultaneously
	RESET-bar Function to Turn Off All Outputs Simultaneously
	SPI-/QSPI-/MICROWIRE-Compatible Serial Interface (MAX4820)
	Serial Digital Output for Daisy Chaining (MAX4820)
	Parallel Interface (MAX4821)
	Low 50µA (max) Quiescent Supply Current
	Space-Saving 20-Pin Thin QFN Package

	Automated Test Equipment (ATE)
	Central Office
	DSL, ADSL Line Cards
	E1/T1 Redundancy
	Industrial Equipment

Key Specifications: Relay Drivers

Part Number

Min. Guaranteed Source Current (mA) @ 2.7V

Output On-Resistance @ 2.7V (max) (Ω)

Quiescent Current (max) (µA)

Features

Number of Channels

Interface

Supply Voltage (V)

RoHS Available

Package

Smallest Available Package (max w/pins) (mm²)

Price^**

MAX4820

•	Daisy-Chainable

•	Integrated Kickback Diodes

•	Power On Reset

•	Thermal Shutdown

SPI

2.3 to 5.5

Yes

THIN QFN/20
TSSOP/20

$1.45 @ 1k

MAX4821

•	Integrated Kickback Diodes

•	Power On Reset

•	Thermal Shutdown

Parallel

$1.45 @ 1k

See All Relay Drivers (7)

Notes:
^**This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Ordering Information

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Devices: 1-16 of 16

MAX4820

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX4820ETP

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044-3*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4820ETP+T

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044+3*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4820ETP+

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044+3*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4820ETP-T

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044-3*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4820EUP+T

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4820EUP+

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4820EUP-T

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4820EUP

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4821

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX4821ETP-T

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044-3*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4821ETP

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044-3*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4821ETP+

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044+3*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4821ETP+T

THIN QFN;20 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2044+3*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4821EUP-T

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4821EUP

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX4821EUP+

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4821EUP+T

TSSOP;20 pin;43 mm²
Dwg: 21-0108F (PDF)
Use pkgcode/variation: U20E+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis