ADM231L–ADM234L/ADM236L–ADM241L

Rev. C | Page 7 of 20

Table 4. Pin Function Descriptions

Mnemonic

Function

Power Supply Input. 5 V ± 10% (5 V ± 5% for ADM233L).

V+

Internally Generated Positive Supply (+10 V nominal) on all parts, except ADM231L and ADM239L. ADM231L and ADM239L

require an external 7.5 V to 13.2 V supply.

V−

Internally Generated Negative Supply (−10 V nominal).

GND

Ground Pin. Must be connected to 0 V.

C+

(ADM231L and ADM239L only) External capacitor (+ terminal) is connected to this pin.

C−

(ADM231L and ADM239L only) External capacitor (– terminal) is connected to this pin.

C1+

(ADM232L, ADM234L, ADM236L, ADM237L, ADM238L, and ADM241L) External capacitor (+ terminal) is connected to this

pin. (ADM233L) The capacitor is connected internally and no external connection to this pin is required.

C1−

(ADM232L, ADM234L, ADM236L, ADM237L, ADM238L, and ADM241L) External capacitor (− terminal) is connected to this

pin. (ADM233L) The capacitor is connected internally and no external connection to this pin is required.

C2+

(ADM232L, ADM234L, ADM236L, ADM237L, ADM238L, and ADM241L) External capacitor (+ terminal) is connected to this

pin. (ADM233L) Internal capacitor connections, Pin 11 and Pin 15, must be connected together.

C2−

(ADM232L, ADM234L, ADM236L, ADM237L, ADM238L, and ADM241L) External capacitor (− terminal) is connected to this

pin. (ADM233L) Internal capacitor connections, Pin 10 and Pin 16, must be connected together.

each input.

Transmitter (Driver) Outputs. These are RS-232 levels (typically ±10 V).

Receiver Inputs. These inputs accept RS-232 signal levels. An internal 5 kΩ pull-down resistor to GND is connected on each input.

Receiver Outputs. These are TTL/CMOS levels.

EN

Enable Input. Active low on ADM236L, ADM239L, and ADM241L. This input is used to enable/disable the receiver outputs.

With EN = low, the receiver outputs are enabled. With EN = high, the outputs are placed in a high impedance state. This

facility is useful for connecting to microprocessor systems.

SD

Shutdown Input. Active high on ADM236L and ADM241L. With SD = high on the ADM236L and ADM241L, the charge pump

is disabled, the receiver outputs are placed in a high impedance state, and the driver outputs are turned off.

NC

No Connect. No connections are required to this pin.

Table 5. ADM236L and ADM241L Truth Table

SD

EN

Status

Transmitters T1 to T5

Receivers R1 to R5

0

0

Normal Operation

Enabled

Enabled

0

1

Normal Operation

Enabled

Disabled

1

0

Shutdown

Disabled

Disabled