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MAXIM New Products - MAX13253 & MAX14920, MAX14921
2013-04-08
MAX13253

1A Spread-Spectrum Push-Pull Transformer Driver for Isolated Power Supplies

Simplifies Isolated Power Designs

Description

The MAX13253 is a 1A push-pull transformer driver designed to provide a simple solution for low-EMI isolated power supplies. The MAX13253 has an internal oscillator and operates from a single +3.0V to +5.5V supply. The transformer’s secondary-to-primary winding ratio defines the output voltage, allowing selection of virtually any isolated output voltage with galvanic isolation.

The MAX13253 features an integrated oscillator driving a pair of N-channel power switches. The driver includes pin-selectable spread-spectrum oscillation and a well-controlled slew rate to reduce EMI. The MAX13253 can optionally be driven by an external clock to further manage EMI. Internal circuitry guarantees a fixed 50% duty cycle to prevent DC current flow through the transformer, regardless of which clock source is used.

The MAX13253 operates with up to 1A of continuous current and features integrated protection including fault detection, overcurrent protection, and thermal shutdown. The MAX13253 includes a low-current shutdown mode to reduce the overall supply current to less than 5µA (max) when the driver is disabled.

The MAX13253 is available in a small, 10-pin, (3mm x 3mm) TDFN package and is specified over the -40°C to +125°C temperature range.

Key Features

  • Simple, Flexible Design
    • +3.0V to +5.5V Supply Range
    • Low RON 300mΩ (max) at 4.5V
    • Up to 90% Efficiency
    • Provides Up to 1A to the Transformer
    • Internal or External Clock Source
    • Internal Oscillator Frequency: 250kHz or 600kHz
    • Optional Spread-Spectrum Oscillation
    • -40°C to +125°C Temperature Range
  • Integrated System Protection
    • Fault Detection and Indication
    • Overcurrent Limiting
    • Undervoltage Lockout
    • Thermal Shutdown
  • Saves Space on Board
    • Small 10-Pin TDFN Package (3mm x 3mm)


MAX14920, MAX14921

High-Accuracy 12-/16-Cell Measurement AFEs

Industry's Most Accurate and Flexible BMS Building Block

Description

The MAX14920/MAX14921 battery measurement analog front-end devices accurately sample cell voltages and provide level shifting for primary/secondary battery packs up to 16 cells/+65V (max). The MAX14920 monitors up to 12 cells, while the MAX14921 monitors up to 16 cells. Both devices simultaneously sample all cell voltages, allowing accurate state-of-charge and source-resistance determination. All cell voltages are level shifted to ground reference with unity gain, simplifying external ADC data conversion.

The devices have a low-noise, low-offset amplifier that buffers differential voltages of up to +5V, allowing monitoring of all common lithium-ion (Li+) cell technologies. The resulting cell voltage error is ±0.5mV.

The devices’ high accuracy make them ideal for monitoring cell chemistries with very flat discharge curves, such as lithium-metal phosphate.

Passive-cell balancing is supported by external FET drivers. Integrated diagnostics in the devices allow open-wire detection and undervoltage/overvoltage alarms. The devices are controlled by a daisy-chainable SPI interface.

The MAX14920 is available in a 64-pin (10mm x 10mm) TQFP package with an exposed pad. The MAX14921 is available in an 80-pin (12mm x 12mm) TQFP package. Both devices are specified over the -40°C to +85°C extended temperature range.


Key Features

  • High Accuracy
    • ±0.5mV (max) Cell Voltage
    • Simultaneous Cell Voltage Sampling
    • Self-Calibration
  • Integrated Diagnostics
    • Open-Wire and Short Fault Detection
    • Undervoltage/Overvoltage Warning
    • Thermal Shutdown
  • High Flexibility
    • SPI Interface
    • 12-Cell and 16-Cell Versions
    • +6V Minimum (3 Cells) Operation
    • +0.5V to +4.5V Cell Voltage Range
    • Integrated Cell-Balancing FET Drivers
    • Integrated 5V LDO
  • Low Power
    • 1µA Shutdown Mode
    • 1µA/10µA Cell Current Draw
 

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