ADM231L–ADM234L/ADM236L–ADM241L
Table 4. Pin Function Descriptions
Mnemonic Function
VCC
V+
Power Supply Input. 5 V 10ꢀ (5 V 5ꢀ for ADM233L).
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).
Ground Pin. Must be connected to 0 V.
GND
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+
C2−
TIN
(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.
(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.
Transmitter (Driver) Inputs. These inputs accept TTL/CMOS levels. An internal 400 kΩ pull-up resistor to VCC is connected to
each input.
Transmitter (Driver) Outputs. These are RS-232 levels (typically 10 V).
TOUT
RIN
ROUT
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.
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.
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.
EN
SD
NC
No Connect. No connections are required to this pin.
Table 5. ADM236L and ADM241L Truth Table
EN
SD
0
0
Status
Transmitters T1 to T5
Enabled
Enabled
Receivers R1 to R5
Enabled
Disabled
0
1
0
Normal Operation
Normal Operation
Shutdown
1
Disabled
Disabled
Rev. C | Page 7 of 20
ADI [ ADI ]
