+3.0V to+5.5V, 1µA, RS-232/RS-485/422

Multiprotocol Transceivers

16

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High Data Rates

The MAX3160/MAX3161/MAX3162 maintain the RS-232

±5.0V required minimum transmitter output voltage even

at high data rates. Figure 11 shows a transmitter loop-

back test circuit. Figure 12 shows a loopback test result

at 250kbps, and Figure 13 shows the same test at

1000kbps. Figure 12 demonstrates a single slew-rate

limited transmitter driven at 250kbps (FAST = GND) into

an RS-232 load in parallel with 1000pF. Figure 13 shows

a single transmitter driven at 1Mbps (FAST asserted),

loaded with an RS-232 receiver in parallel with 1000pF.

These transceivers maintain the RS-232 ±5.0V minimum

transmitter output voltage at data rates up to 1Mbps.

256 Transceivers on the Bus

The standard RS-485 receiver input impedance is

12k

Ω (one-unit load), and the standard driver can drive

up to 32-unit loads. The MAX3160 has a 1/4-unit load

RSCCC

INPUTS

OUTPUTS

SHDN

RS-485/

DI/T1IN,

DE485/T2IN

Z(B)/T1OUT,

Y(A)/T2OUT

0

X

X

1/8-unit load

10

0

1

10

1

0

1

1

X

RS-485 mode

-232

Table 1. MAX3160

INPUTS

OUTPUTS

SHDN

RS-485/

DI/T1IN,

DE485/T2IN

T1OUT,

T2OUT

0

X

X

High-Z

10

0

1

10

1

0

1

1

X

High-Z

RSCCC

-232

Table 2. MAX3161

INPUTS

OUTPUTS

SHDN

TE232

T1IN,T2IN

T1OUT,

T2OUT

0

X

X

High-Z

X

0

X

High-Z

11

0

1

11

1

0

Table 3. MAX3162

INPUTS

OUTPUTS

SHDN

RS-485/

RS-232

B/R1IN,

A/R2IN

R1OUT,

RO/R2OUT

X0

0

1

X0

1

0

X

0

Inputs Open

1

X1

X

R1OUT

High-Z,

RO/R2OUT in

RS-485 mode

Table 4. MAX3160

INPUTS

OUTPUTS

SHDN

RS-485/

R1IN, R2IN

R1OUT,

RO/R2OUT

X0

0

1

X0

1

0

X

0

Inputs Open

1

X1

X

R1OUT

High-Z,

RO/R2OUT in

RS-485 mode

RSCCC

-232

Table 5. MAX3161

RS-232 Transmitters

INPUTS

OUTPUTS

SHDN

R1IN,R2IN

R1OUT,

R2OUT

X

1

X

High-Z

X0

0

1

X0

1

0

X

0

Inputs open

1

RSCCC

-232

Table 6. MAX3162

RS-232 Receivers

Truth Tables