3V to 5.5V, Up to 250kbps True RS-232 Transceiver with 4µA AutoShutdown Plus and Power On Reset

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The MAX3320 combines a microprocessor (µP) supervisory circuit with an RS-232 transceiver. The power-on reset performs a single function: it asserts a reset signal whenever the VCC supply voltage declines below a preset threshold, staying asserted for at least 100ms after VCC rises above the reset threshold. The MAX3320 has an active-low RESET output, which is guaranteed to be in the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds suitable for operation with a variety of supply voltages are available.

The MAX3320 transceivers have a proprietary low-dropout transmitter output stage, enabling true RS-232 performance with a dual charge pump powered from a +3V to +5.5V supply. The device requires only four small 0.1µF external charge-pump capacitors, and is guaranteed to run at data rates of up to 250kbps. It comes in the space-saving 20-pin SSOP package.
MAX3320A, MAX3320B, MAX3320L, MAX3320T: Typical Operating Circuit MAX3320A, MAX3320B, MAX3320L, MAX3320T: Typical Operating Circuit Enlarge+

Key Features

  • Precise Monitoring of 5V and 3.3V Power-Supply Voltages:
    • 100ms (min) Power-On active-low RESET Pulse Width
    • Power-Supply Transient Immunity
    • Guaranteed active-low RESET Valid to VCC = 1V
  • 4µA Supply Current Achieved with AutoShutdown Plus™
  • Receivers Always Active
  • Power-On Reset Always Active
  • 4µA Low-Power Shutdown
  • 250kbps Guaranteed Data Rate


  • Handheld Equipment
  • Palmtop Computers
  • Peripherals
  • Portable Battery-Powered Equipment
  • Printers
Part NumberVSUPPLY
TxRxData Rate
Internal Charge PumpExt. CapsCap. Value
Rx Active in ShutdnPackage/PinsBudgetary
mintypnomSee Notes
$3.91 @1k
See All RS-232 Line Driver/Receivers (136)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Quality and Environmental Data

Request Reliability Report for: MAX3320B 
Lead-Free Package Tin (Sn) Whisker Reports
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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05/29/2020 - 05/31/2020, Detroit, MI
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