Overview
The MAX3221IPWRG4, produced by Texas Instruments, is a 3-V to 5.5-V single-channel RS-232 line driver and receiver. This device is designed to provide a reliable and efficient interface between an asynchronous communication controller and a serial-port connector. It meets or exceeds the requirements of TIA/EIA-232-F and ITU V.28 standards, ensuring compliance with RS-232 specifications. The MAX3221IPWRG4 features a dual charge-pump circuit that allows operation from a single supply voltage, making it suitable for a wide range of applications, including palmtop PCs, hand-held equipment, and other devices requiring RS-232 communication.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC to GND | -0.3 | 6 | V | |
| Input Voltage (DIN, EN, FORCEOFF, FORCEON) | -0.3 | 6 | V | |
| Receiver Input Voltage (RIN) | -25 | 25 | V | |
| Operating Free-Air Temperature (MAX3221C) | 0 | 70 | °C | |
| Operating Free-Air Temperature (MAX3221I) | -40 | 85 | °C | |
| Data Signaling Rate | 250 | kbps | ||
| Driver Output Slew Rate | 30 | V/μs | ||
| ESD Protection | ±15 kV |
Key Features
- RS-232 bus-pin ESD protection exceeds ±15 kV using the Human Body Model (HBM).
- Meets or exceeds the requirements of TIA/EIA-232-F and ITU V.28 standards.
- Operates with a single 3-V to 5.5-V supply.
- Data signaling rates up to 250 kbps.
- Maximum driver output slew rate of 30 V/μs.
- Low standby current: 1 μA typical.
- External capacitors: 4 × 0.1 μF required for operation.
- Accepts 5-V logic input with a 3.3-V supply.
- Automatic power-down feature controlled by FORCEON and FORCEOFF inputs for the driver, and EN input for the receiver.
- INVALID output indicates valid or invalid receiver input status.
Applications
- Palmtop PCs and other portable computers.
- Hand-held equipment and devices.
- Industrial automation and control systems.
- Medical devices requiring RS-232 communication.
- Point-of-sale terminals and other commercial equipment.
Q & A
- What is the operating voltage range of the MAX3221IPWRG4?
The MAX3221IPWRG4 operates with a single supply voltage ranging from 3 V to 5.5 V.
- What is the maximum data signaling rate supported by the MAX3221IPWRG4?
The device supports data signaling rates up to 250 kbps.
- What level of ESD protection does the MAX3221IPWRG4 offer?
The device offers ESD protection exceeding ±15 kV using the Human Body Model (HBM).
- How is the automatic power-down feature controlled in the MAX3221IPWRG4?
The automatic power-down feature for the driver is controlled by the FORCEON and FORCEOFF inputs, while the receiver is controlled by the EN input.
- What is the purpose of the INVALID output in the MAX3221IPWRG4?
The INVALID output indicates whether the receiver input is valid or invalid, going low if the input voltage is between –0.3 V and 0.3 V for more than 30 μs.
- Can the MAX3221IPWRG4 be safely connected to an active remote RS-232 device when unpowered?
Yes, the MAX3221IPWRG4 can be safely connected to an active remote RS-232 device when it is unpowered.
- What type of capacitors are required for the charge pump circuit in the MAX3221IPWRG4?
The charge pump circuit requires four external capacitors, typically 0.1 μF each.
- Does the MAX3221IPWRG4 support 5-V logic input with a 3.3-V supply?
Yes, the device accepts 5-V logic input even when operating with a 3.3-V supply.
- What is the typical standby current of the MAX3221IPWRG4?
The typical standby current is 1 μA.
- What are some common applications of the MAX3221IPWRG4?
Common applications include palmtop PCs, hand-held equipment, industrial automation, medical devices, and point-of-sale terminals.
