Overview
The MAX3221CDBRG4, produced by Texas Instruments, is a 3-V to 5.5-V 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 features one line driver, one line receiver with a dedicated enable pin, and a dual charge-pump circuit. The MAX3221CDBRG4 meets or exceeds the requirements of TIA/EIA-232-F and ITU V.28 standards, ensuring compliance with RS-232 specifications.
The device operates at data signaling rates up to 250 kbps and includes automatic power-down features to reduce power consumption when the serial port is inactive. It also offers high ESD protection, with RS-232 bus-pin ESD protection exceeding ±15 kV using the human body model (HBM).
Key Specifications
| Parameter | Test Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage (VCC) | 3.0 | 3.3 / 5.0 | 5.5 | V | |
| Driver High-Level Input Voltage (VIH) | VCC = 3.3 V / VCC = 5 V | 2.0 / 2.4 | V | ||
| Driver Low-Level Input Voltage (VIL) | 0.8 | V | |||
| Receiver Input Voltage | -25 | 25 | V | ||
| Operating Free-Air Temperature | MAX3221C / MAX3221I | 0 / -40 | 70 / 85 | °C | |
| Driver Output Slew Rate | VCC = 3.3 V, RL = 3 kΩ to 7 kΩ, CL = 150 to 1000 pF | 6 | 30 | V/μs | |
| Standby Current | 1 | μA |
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 3-V to 5.5-V VCC supply
- Operates up to 250 kbps
- One driver and one receiver
- Low standby current: 1 μA typical
- External capacitors: 4 × 0.1 μF
- Accepts 5-V logic input with 3.3-V supply
- Automatic power-down feature for power savings
Applications
- Industrial PCs
- Wired networking
- Data center and enterprise computing
- Battery-powered systems
- PDAs
- Notebooks and laptops
- Palmtop PCs
- Hand-held equipment
Q & A
- What is the operating voltage range of the MAX3221CDBRG4?
The MAX3221CDBRG4 operates with a supply voltage (VCC) range of 3.0 V to 5.5 V.
- What is the maximum data rate supported by the MAX3221CDBRG4?
The device supports data signaling rates up to 250 kbps.
- What kind of ESD protection does the MAX3221CDBRG4 offer?
The device offers RS-232 bus-pin ESD protection exceeding ±15 kV using the human body model (HBM).
- Does the MAX3221CDBRG4 have automatic power-down features?
Yes, the device has an automatic power-down feature that disables the drivers for power savings when the serial port is inactive.
- What are the typical standby current and operating free-air temperature ranges for the MAX3221CDBRG4?
The typical standby current is 1 μA, and the operating free-air temperature range is 0°C to 70°C for the MAX3221C and -40°C to 85°C for the MAX3221I.
- How many external capacitors are required for the MAX3221CDBRG4 to operate?
The device requires four small external capacitors (4 × 0.1 μF) for operation.
- Can the MAX3221CDBRG4 accept 5-V logic input with a 3.3-V supply?
Yes, the device can accept 5-V logic input with a 3.3-V supply.
- What are some common applications of the MAX3221CDBRG4?
Common applications include industrial PCs, wired networking, data center and enterprise computing, battery-powered systems, PDAs, notebooks, laptops, palmtop PCs, and hand-held equipment.
- How does the INVALID output work on the MAX3221CDBRG4?
The INVALID output goes high when the receiver has a valid input (voltage greater than 2.7 V or less than -2.7 V) and goes low when the receiver input voltage is between -0.3 V and 0.3 V for more than 30 μs.
- What is the purpose of the FORCEON and FORCEOFF inputs on the MAX3221CDBRG4?
The FORCEON and FORCEOFF inputs control the automatic power-down feature of the device. When FORCEON is low and FORCEOFF is high, the device can automatically power down the driver to save power.
