Analog Devices ADM3222, ADM3202, ADM1385 Datasheet

Low Power, +3.3 V, RS-232

FEATURES 460 kbps Data Rate Specified at +3.3 V Meets EIA-232E Specifications

0.1 F Charge Pump Capacitors Low Power Shutdown (ADM3222E and ADM1385) DIP, SO, SOIC, SSOP and TSSOP Package Options Upgrade for MAX3222/32 and LTC1385

APPLICATIONS General Purpose RS-232 Data Link Portable Instruments Printers Palmtop Computers PDAs

GENERAL DESCRIPTION

The ADM3202/ADM3222/ADM1385 transceivers are high speed, 2-channel RS-232/V.28 interface devices which operate from a single +3.3 V power supply.

Low power consumption and a shutdown facility (ADM3222/ ADM1385) makes them ideal for battery powered portable instruments.

The ADM3202/ADM3222/ADM1385 conforms to the EIA232E and CCITT V.28 specifications and operates at data rates up to 460 kbps.

Four external 0.1 µF charge pump capacitors are used for the voltage doubler/inverter permitting operation from a single +3.3 V supply.

The ADM3222 contains additional enable and shutdown circuitry. The EN input may be used to three-state the receiver outputs. The SD input is used to power down the charge pump and transmitter outputs reducing the quiescent current to less than 0.5 µA. The receivers remain enabled during shutdown unless disabled using EN.

The ADM1385 contains a driver disable mode and a complete shutdown mode.

The ADM3202 is available in a 16-lead DIP, narrow and wide SOIC as well as a space saving 20-lead TSSOP package. The ADM3222 is available in 18-lead DIP, SO and in 20-lead SSOP and TSSOP. The ADM1385 is available in a 20-lead SSOP package, which is pin compatible with the LTC1385 CG.

Line Drivers/Receivers

ADM3202/ADM3222/ADM1385

FUNCTIONAL BLOCK DIAGRAMS

+3.3V INPUT

CMOS

INPUTS

CMOS

OUTPUTS

CMOS

INPUTS

CMOS

OUTPUTS

CMOS

INPUTS

CMOS

OUTPUTS

0.1F 10V

OUT

0.1F 10V

OUT

EN SD

0.1F 10V

OUT

C1–

+6.6V TO –6.6V

C2+

C2–

+3.3V TO +6.6V

C1+

C1–

+6.6V TO –6.6V

C2+

C2–

+3.3V TO +6.6V

C1+

C1–

+6.6V TO –6.6V

C2+

C2–

VOLTAGE DOUBLER

VOLTAGE INVERTER

GND

VOLTAGE

DOUBLER

VOLTAGE INVERTER

GND

VOLTAGE

DOUBLER

VOLTAGE INVERTER

GND

+3.3V TO +6.6V

C1+

V+

V–

ADM3202

*INTERNAL 5k PULL-DOWN RESISTOR ON EACH RS-232 INPUT

+3.3V INPUT

V+

V–

ADM3222

*INTERNAL 5k PULL-DOWN RESISTOR ON EACH RS-232 INPUT

+3.3V INPUT

V+

V–

0.1F 10V

ADM1385

*INTERNAL 5k PULL-DOWN RESISTOR ON EACH RS-232 INPUT

0.1F

6.3V

0.1F 10V

OUT

0.1F

6.3V

0.1F 10V

OUT

0.1F

6.3V

0.1F

EIA/TIA-232 OUTPUTS

EIA/TIA-232 INPUTS*

0.1F

EIA/TIA-232 OUTPUTS

EIA/TIA-232 INPUTS*

0.1F

EIA/TIA-232 OUTPUTS

EIA/TIA-232 INPUTS*

REV. A

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ADM3202/ADM3222/ADM1385–SPECIFICATIONS

(VCC = +3.3 V  0.3 V, C1–C4 = 0.1 F. All specifications T

Parameter Min Typ Max Unit Test Conditions/Comments

DC CHARACTERISTICS

Operating Voltage Range 3.0 3.3 5.5 V

Power Supply Current 1.3 2.1 mA No Load

Shutdown Supply Current 0.01 0.5 µA

LOGIC

Input Logic Threshold Low, V Input Logic Threshold High, V CMOS Output Voltage Low, V CMOS Output Voltage High, V

INL

INH

2.0 V T

VCC – 0.6 V I Input Leakage Current 0.01 ± 1 µAT Output Leakage Current ± 10 µA Receivers Disabled

RS-232 RECEIVER

EIA-232 Input Voltage Range –30 +30 V EIA-232 Input Threshold Low 0.6 1.2 V EIA-232 Input Threshold High 1.6 2.4 V EIA-232 Input Hysteresis 0.4 V EIA-232 Input Resistance 3 5 7 kΩ

RS-232 TRANSMITTER

Output Voltage Swing (RS-232) ± 5.0 ± 5.2 V V

Output Voltage Swing (RS-562) ± 3.7 V V Transmitter Output Resistance 300 Ω V RS-232 Output Short Circuit Current ± 15 mA Output Leakage Current ± 25 µA SD = Low, V

TIMING CHARACTERISTICS

Maximum Data Rate 460 kbps VCC = 3.3 V, RL = 3 kΩ to 7 kΩ, CL = 50 pF to Receiver Propagation Delay 1000 pF. One Tx Switching

TPHL 0.4 1 µs

TPLH 0.4 1 µs Transmitter Propagation Delay 300 750 ns R Receiver Output Enable Time 200 ns Receiver Output Disable Time 200 ns Transmitter Skew 30 ns Receiver Skew 300 ns Transition Region Slew Rate Measured from +3 V to –3 V or –3 V to +3 V,

61030V/µsR 41030V/µsR

*ADM1385: Input leakage current typically –10 µA when TIN = GND.

Specifications subject to change without notice.

to T

MIN

unless otherwise noted.)

MAX

810 mAR

0.8 V T

0.4 V I

OUT

with 3 kΩ to Ground

= 3 kΩ to GND

= 1.6 mA = –1 mA

= GND to VCC*

= 3.3 V. All Transmitter Outputs Loaded

= 3.0 V = 0 V, V

OUT

= ± 2 V

= 12 V

= 3 kΩ, CL = 1000 pF

= +3.3 V = 3 kΩ, CL = 1000 pF, TA = +25°C = 3 kΩ, CL = 2500 pF, TA = +25°C

–2–

REV. A

ADM3202/ADM3222/ADM1385

ABSOLUTE MAXIMUM RATINGS*

(TA = +25°C unless otherwise noted)

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V

V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V

– 0.3 V) to +14 V

V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –14 V

Input Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (V+, +0.3 V)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 30 V

Output Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 15 V

OUT

. . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (VCC + 0.3 V)

OUT

Short Circuit Duration

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous

OUT

Power Dissipation

Power Dissipation N-16 . . . . . . . . . . . . . . . . . . . . . 450 mW

(Derate 6 mW/°C above +50°C)

, Thermal Impedance . . . . . . . . . . . . . . . . . . . 117°C/W

Power Dissipation R-16 . . . . . . . . . . . . . . . . . . . . . 450 mW

(Derate 6 mW/°C above +50°C)