MAX3325:3V, Dual RS-232 Transceiver with LCD Supply and Contrast Controller

+3V RS-232 Transceiver Provides Power/Bias to LCD Display

The MAX3325 integrates a two-transmitter, two-receiver RS-232 transceiver with an LCD supply plus temperature-compensated contrast control. It is intended for small 3V instruments requiring a 5V supply for either logic or an LCD display, an adjustable bias signal for contrast, LCD temperature compensation, and an RS-232 interface for serial communications. The 5V supply is a regulated charge pump followed by a low-dropout (LDO) linear regulator capable of supplying 11mA for the 5V LCD power. The MAX3325 has an internal 6-bit digital-to-analog converter (DAC) providing 64 contrast levels, plus an internal temperature sensor that compensates the LCD's contrast for changes in ambient temperature. The LCD contrast can be designed for any voltage range from -5V to +2V. The MAX3325's 250kbps RS-232 transceiver meets all EIA-232E specifications with input voltages from +3.0V to +3.6V. Both the RS-232 section and the LCD supply circuitry can be independently placed in shutdown, tailoring power consumption for battery-powered equipment. The MAX3325 is available in 28-pin SSOP and narrow DIP packages.

Key Features
  • +3.0V to +3.6V Single-Supply Operation
  • Provides 5.0V Regulated Output at 11mA in 3V Systems
  • 6-Bit DAC with Up/Down Interface for LCD Contrast Adjustment
  • Selectable Positive or Negative LCD Bias
  • Meets EIA-232E Specifications at 250kbps-Guaranteed
  • 1µA Shutdown Mode
  • Uses Small 0.22µF Capacitors-No Inductors Required
  • Temperature Sensor for LCD Contrast Compensation
  • Simple, Flexible Design Procedure for a Broad Range of LCD Displays
MAX3325: Typical Operating Circuit
MAX3325: Typical Operating Circuit
Applications/Uses
  • GPS Receivers
  • Handheld Medical Equipment
  • Handy Terminals
  • Industrial Test Equipment
  • PDAs and Palmtop Computers
DataSheet
titleDownload file
MAX3325 Data SheetMAX3325.pdf
Parametrics
Part NumberVSUPPLY
(V)
TxRxData Rate
(kbps)
ICC
(mA)
Internal Charge PumpExt. CapsCap. Value
(µF)
Rx Active in ShutdnPackage/PinsBudgetary
Price
mintypnomSee Notes
MAX33253.3222502Yes40.222PDIP(N)/28
SSOP/28
$3.73 @1k
Related Products
  • MAX3222E:±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
  • MAX3232E:±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
  • MAX3224:1µA Supply Current, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plus
  • MAX3225:1µA Supply Current, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plus
  • MAX3224E:±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plus
  • MAX3225E:±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plus
  • MAX3222:3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232 Transceivers Using Four 0.1µF External Capacitors
  • MAX3232:3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232 Transceivers Using Four 0.1µF External Capacitors
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX3325CAINo Longer AvailableSSOP,;28 pin;81.6 mm²0°C to +70°CSee data sheet
MAX3325CAI-TNo Longer AvailableSSOP;28 pin0°C to +70°CSee data sheet
MAX3325CNINo Longer AvailablePDIP(N),;28 pin;289.5 mm²0°C to +70°CNo
MAX3325EAINo Longer AvailableMAX3325EAI+SSOP,;28 pin;81.6 mm²-40°C to +85°CSee data sheet
MAX3325EAI+ActiveSSOP,;28 pin;81.6 mm²-40°C to +85°CLead Free
MAX3325EAI+TActiveSSOP,;28 pin;81.6 mm²-40°C to +85°CLead Free
MAX3325EAI-TNo Longer AvailableMAX3325EAI+TSSOP,;28 pin;81.6 mm²-40°C to +85°CSee data sheet
MAX3325ENINo Longer AvailablePDIP(N),;28 pin;289.5 mm²-40°C to +85°CNo
MAX3325.pdf MAX3325
MAX3325.pdf MAX3325