MAXIM MAX4820, MAX4821 User Manual

General 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 8­bit 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 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 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 this device
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.

Applications

Central Office

ATE

DSL, ADSL Line Cards

Industrial Equipment

E1/T1 Redundancy

Features

♦ 8 Independent Output Channels

♦ Built-In Inductive Kickback Protection

♦ Drive +3V and +5V Relays

♦ Guaranteed 70mA (min) Coil Drive Current
♦ SET Function to Turn On All Outputs

Simultaneously

♦ RESET 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

MAX4820/MAX4821

+3.3V/+5V, 8-Channel, Cascadable Relay Drivers

with Serial/Parallel Interface

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

Ordering Information

19-2751; Rev 0; 1/03

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.

*For maximum heat dissipation, packages have an exposed pad
(EP) on the bottom. Solder exposed pad to GND.

Pin Configurations continued at end of data sheet.

Typical Application Circuits and Functional Diagrams

appear at end of data sheet.

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.

查询MAX4820供应商

PART TEMP RANGE PIN-PACKAGE

MAX4820ETP* -40°C to +85°C 20 Thin QFN-EP

MAX4820EUP* -40°C to +85°C 20 TSSOP

MAX4821ETP* -40°C to +85°C 20 Thin QFN-EP

MAX4821EUP* -40°C to +85°C 20 TSSOP

TOP VIEW

SET

VCCOUT1

OUT2

20

19

18

17

16 PGND

1

RESET

DIN

SCLK

2

CS

3

4

5DOUT

MAX4820

6

7

N.C.

GND

THIN QFN

8

OUT8

9

OUT7

10PGND

OUT3

15

OUT4

14

COM

13

12

OUT5

11

OUT6

MAX4820/MAX4821

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

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3V to +5.5V, V

COM

= VCC, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

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.

(All voltages referenced to GND.)
V

CC

, COM..............................................................-0.3V to +6.0V

OUT_........................................................-0.3V to (V

COM

+ 0.3V)

CS, SCLK, DIN, SET, RESET, A0, A1, A2, LVL......-0.3V to +6.0V

DOUT..........................................................-0.3V to (V

CC

+ 0.3V)

Continuous OUT_ Current (all outputs turned on) ............150mA

Continuous OUT_ Current (single output turned on) ........300mA

Continuous Power Dissipation (T

A

= +70°C)

20-Lead Thin QFN

(derate 16.9mW/°C above +70°C).................................1350mW

θ

JA

.........................................................................59.3°C/W

20-Pin TSSOP

(derate 21.7mW/°C above +70°C).................................1739mW

θ

JA

............................................................................46°C/W

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Soldering Temperature (10s) ...........................................+300°C

Operating Voltage V

Quiescent Current I

Thermal Shutdown 160 °C

Power-On Reset 0.8 1.5 2.2 V

Power-On Reset Hysteresis 140 mV

DIGITAL INPUTS (SCLK, DIN, CS, LVL, A0, A1, A2, RESET, SET)

Input Logic High Voltage V

Input Logic Low Voltage V

Input Logic Hysteresis V

Input Leakage Currents I

CIN Input Capacitance C

DIGITAL OUTPUT (DOUT)

DOUT Low Voltage V

DOUT High Voltage V

RELAY OUTPUT DRIVERS (OUT1–OUT8)

OUT_ Drive Current

OUT_ On-Resistance R

OUT_ Voltage V

I

OUT

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Off-Leakage Current I

CC

I

Q

IH

IL

HYST

LEAK

IN

OL

OH

ON

OUT

LEAK

OUT

logic inputs = 0 or V

VCC = 3.3V 2.0

VCC = 5V 2.4

VCC = 3.3V 0.6

VCC = 5V 0.8

Input voltages = 0 or 5.5V -1.0 0.01 +1.0 µA

I

SINK

I

SOURCE

VCC = 2.7V 70

V

CC

VCC = 2.7V 2 6 Ω

_VCC = 3.0V, I

V

OUT

_ = 0,

= 6mA 0.4 V

= 0.5mA VCC - 0.5 V

= 4.5V 70

_ = 70mA 0.4 V

OUT

_ = VCC, all outputs off -1 +1 µA

VCC = 3.6V 15 50

CC V

= 5.5V 20 70

CC

2.3 5.5 V

150 mV

5pF

µA

V

V

mA

Kickback Diode Forward Voltage V

FORWIOUT

_ = 150mA (Note 2) 1.5 V

MAX4820/MAX4821

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

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3V to +5.5V, V

COM

= VCC, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

Note 1: Specifications at -40°C are guaranteed by design and not production tested.
Note 2: After relay turn-off, inductive kickback may momentarily cause the voltage at OUT_ to exceed V

COM

. This is considered part

of normal operation and will not damage the device.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SPI TIMING (MAX4821)

Turn-On Time (OUT_) t

Turn-Off Time (OUT_) t

SCLK Frequency f

Cycle Time t

CS Fall to SCLK Rise Setup t
CS Rise to SCLK Hold t

SCLK High Time t

SCLK Low Time t

Data Setup Time t

Data Hold Time t

SCLK Fall to DOUT Valid t

Rise Time (DIN, SCLK, CS, SET,
RESET)

Fall Time (DIN, SCLK, CS,

RESET, SET)
RESET Min Pulse Width t

SET Min Pulse Width t

PARALLEL TIMING (MAX4820)

Turn-On Time t

Turn-Off Time t

LVL Setup Time t

LVL Hold Time t
Address to CS Setup Time t
Address to CS Hold Time t

Rise Time (A2, A1, A0, LVL) t

Fall Time (A2, A1, A0, LVL) t

RESET Pulse Width t
SET Pulse Width t

From rising edge of CS, RL = 50Ω,
C

= 50pF

L

From rising edge of CS, RL = 50Ω,
C

= 50pF

L

CL

50% of SCLK to 10% of DOUT,

= 50pF

C

L

20% of VCC to 70% of VCC, CL = 50pF 2 µs

20% of VCC to 70% of VCC, CL = 50pF 2 µs

From rising edge of CS, RL = 50Ω,
C

= 50pF

L

From rising edge of CS, RL = 50Ω,

= 50pF

C

L

20% of VCC to 70% of VCC, CL = 50pF 2 µs

20% of VCC to 70% of VCC, CL = 50pF 2 µs

CH

ON

OFF

SCLK

+ t

CSS

CSH

CH

CL

DS

DH

DO

t

SCR

t

SCF

RW

SW

ON

OFF

LS

LH

AH

AS

SCR

SCF

RW

SW

1.0 µs

1.0 µs

0 2.1 MHz

480 ns

240 ns

240 ns

190 ns

190 ns

100 ns

0ns

85 120 ns

70 ns

70 ns

1µs

1µs

100 ns

0ns

100 ns

0ns

70 ns

70 ns

MAX4820/MAX4821

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

4 _______________________________________________________________________________________

Typical Operating Characteristics

(V

COM

= VCC, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX4820 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

5.14.74.33.93.53.12.7

5

10

15

20

25

0

2.3 5.5

ALL LOGIC INPUTS = 0

SUPPLY CURRENT
vs. TEMPERATURE

MAX4820 toc02

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

603510-15

5

10

15

20

25

0

-40 85

VCC = 5V

VCC = 5.5V

VCC = 2.3V

VCC = 3.3V

SUPPLY CURRENT

vs. INPUT LOGIC VOLTAGE

MAX4820 toc03

INPUT LOGIC VOLTAGE (V)

SUPPLY CURRENT (µA)

4321

100

200

300

400

500

600

700

800

900

1000

0

05

VCC = 3.3V

VCC = 5V

ALL LOGIC INPUTS
CONNECTED

ON-RESISTANCE

vs. SUPPLY VOLTAGE

MAX4820 toc04

SUPPLY VOLTAGE (V)

R

ON

(Ω)

5.14.74.33.93.53.12.7

0.5

1.0

1.5

2.0

2.5

3.0

0

2.3 5.5

I

OUT_SINK

= 70mA

ON-RESISTANCE

vs. TEMPERATURE

MAX4820 toc05

TEMPERATURE (°C)

R

ON

(Ω)

603510-15

0.5

1.0

1.5

2.0

2.5

3.0

0

-40 85

V

CC

= 3.3V

V

CC

= 2.3V

V

CC

= 5.5V

V

CC

= 5V

I

OUT_SINK

= 70mA

POWER-ON RESET VOLTAGE

vs. TEMPERATURE

MAX4820 toc06

TEMPERATURE (°C)

POWER-ON RESET VOLTAGE (V)

6035-15 10

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

0

-40 85

OUTPUT OFF-LEAKAGE CURRENT

vs. SUPPLY VOLTAGE

MAX4820 toc07

SUPPLY VOLTAGE (V)

OUTPUT OFF-LEAKAGE (nA)

5.14.73.9 4.33.1 3.52.7

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0

2.3 5.5

OUTPUT OFF-LEAKAGE CURRENT

vs. TEMPERATURE

MAX4820 toc08

TEMPERATURE (°C)

OUTPUT OFF-LEAKAGE (nA)

6035-15 10

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

0

-40 85

VCC = 5.5V

VCC = 5V

VCC = 2.3V

VCC = 3.3V

OUT_ TURN-ON/TURN-OFF DELAY TIMES

vs. SUPPLY VOLTAGE

MAX4820 toc09

SUPPLY VOLTAGE (V)

t

ON

/t

OFF

DELAY TIME (ns)

5.14.74.33.93.53.12.7

30

40

50

60

70

80

20

2.3 5.5

RL = 50Ω
C

L

= 50pF

t

ON

t

OFF