Datasheet MAX1932 (Maxim)

EVALUATION KIT AVAILABLE
MAX1932 Digitally Controlled, 0.5% Accurate, Safest APD Bias Supply General Description Benefits and Features
The MAX1932 generates a low-noise, high-voltage output
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Unique Architecture Delivers Excellent Accuracy for to bias avalanche photodiodes (APDs) in optical Improved System Performance receivers. Very low output ripple and noise is achieved by • 0.5% Accurate Output a constant-frequency, pulse-width modulated (PWM) • Low Ripple Output (< 1mV) boost topology combined with a unique architecture that
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Protection Features Guarantee Safe Operation maintains regulation with an optional RC or LC post filter • Accurate High-Side Current Limit inside its feedback loop. A precision reference and error amplifier maintain 0.5% output voltage accuracy. • Avalanche Indicator Flag
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Output-Voltage Flexibility Facilitates Multiple The MAX1932 protects expensive APDs against adverse Applications and Design Approaches operating conditions while providing optimal bias. Traditional boost converters measure switch current for • 4.5V to 90V Output protection, whereas the MAX1932 integrates accurate • Set Output Voltage via 8-Bit SPI-Compatible high-side current limiting to protect APDs under Internal DAC, External DAC, or External Resistors avalanche conditions. A current-limit flag allows easy cali-
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Small Circuit Footprint Reduces Equipment Size bration of the APD operating point by indicating the pre- • 12-Pin, 4mm x 4mm Thin QFN Package cise point of avalanche breakdown. The MAX1932 control • Circuit Height < 2mm scheme prevents output overshoot and undershoot to
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Commonly Available 2.7V to 5.5V Input Voltage provide safe APD operation without data loss. Range The output voltage can be accurately set with either external resistors, an internal 8-bit DAC, an external DAC, or other voltage source. Output span and offset are independently settable with external resistors. This
Ordering Information
optimizes the utilization of DAC resolution for applica- tions that may require limited output voltage range, such
PART TEMP RANGE PIN-PACKAGE
as 4.5V to 15V, 4.5V to 45V, 20V to 60V, or 40V to 90V. MAX1932ETC -40°C to +85°C 12 Thin QFN
Applications
Optical Receivers and Modules Fiber Optic Network Equipment Telecom Equipment Laser Range Finders
Typical Application Circuit
PIN Diode Bias Supply INPUT 2.7V TO 5.5V
Pin Configuration
VIN TE MAX1932 APD BIAS OUTPUT CS VIN GA 4.5V TO 90V COMP 12 11 10 GATE SCLK 1 9 GND CS DIN 2 MAX1932 8 COMP CS+ DAC INPUTS SCLK CS- CL 3 7 FB DIN AVALANCHE 4 5 6 INDICATOR CL FLAG GND FB CS+ CS- DACOUT DACOUT 19-2555; Rev 2; 5/15