Part Number : ADM232AAN
Function : High-Speed, 5 V, 0.1 uF CMOS RS-232 Drivers/Receivers
Package : 16Pin DIP type
Manufacturers : Analog Devices
The ADM222/ADM232A/ADM242 are high-speed RS-232 drivers/receivers requiring a single digital 5 V supply. The RS-232 standard requires transmitters that will deliver ±5 V minimum on the transmission channel and receivers that can accept signal levels down to ±3 V. The parts achieve this by integrating stepup voltage converters and level-shifting transmitters and receivers onto the same chip. CMOS technology is used to keep the power dissipation to an absolute minimum. All devices contain an internal charge pump voltage doubler and a voltage inverter that generates ± 10 V from the 5 V input. Four external 0.1 μF capacitors are required for the internal charge pump voltage converter.
Charge Pump DC-DC Voltage Converter
The Charge Pump Voltage converter consists of an oscillator and a switching matrix. The converter generates a ±10 V supply from the input 5 V level. This is done in two stages using a switched capacitor technique. The 5 V input supply is doubled to 10 V using capacitor C1 as the charge storage element. The –10 V level is also generated from the input 5 V supply using C1 and C2 as the storage elements.
1. 200 kB/s Transmission Rate
2. Small (0.1 F) Charge Pump Capacitors
3. Single 5 V Power Supply
4. Meets All EIA-232-E and V.28 Specifications
5. Two Drivers and Two Receivers
6. On-Board DC-DC Converters