Key Specs
No verified spec values available.
When To Use
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24V industrial control supply → 7.5V @ 0.5A: The 25V maximum operating voltage and 0.5A continuous gate driver output current match this application well, ensuring robust operation without overstressing the device. Using a generic synchronous buck controller with a lower gate driver current rating risks incomplete MOSFET drive, causing slow switching and excessive heat buildup leading to thermal runaway.
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Battery-powered system with 16.5V turn-on threshold: The precise turn-on threshold window of 15.5V to 17.5V provides reliable undervoltage lockout, preventing system brownouts. A simple LDO regulator would lack this built-in UVLO, risking latch-up or erratic startup when battery voltage dips near cutoff.
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Switching frequency set by external RC at ~68kHz: The oscillator frequency range of 58kHz to 78kHz with a well-defined ramp amplitude and valley voltage enables stable PWM control in applications needing moderate switching speed with low EMI. A high-frequency buck controller designed for >500kHz would cause unnecessary switching losses and increased EMI in this frequency range.
When Not To Use
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>1A output current load: The 0.5A continuous gate driver current and 12mA maximum output current limit are insufficient. Use a multi-phase buck controller to support higher current with balanced load sharing.
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Battery-operated device requiring ultra-low quiescent current: The start-up supply current of 250mA (typ) and supply current on the order of 8.5–12mA make this part unsuitable. Use a low-IQ PFM buck controller designed for μA-level quiescent current.
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High-frequency switching >500kHz needed for compact inductors: The oscillator frequency maxes at 78kHz, limiting switching speed and inductor size reduction. Use a high-frequency buck controller for efficient operation above 500kHz.
Application Notes
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The switching node (SW) must be routed with a short, low-inductance path to minimize voltage overshoot and ringing, as the gate driver can source up to 1.5A peak current.
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Pins associated with the oscillator and ramp control (externally set by R and C) are noise-sensitive; keep these components physically close and shielded from high-current loops to maintain stable switching frequency.
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The enable/synchronization input has a rising threshold around 2.6V with 0.4V hysteresis; noise on this line can cause unintended switching or lockout—use a clean, filtered source and a series resistor if needed.
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The internal error and current amplifiers have high DC gain (100dB and 110dB respectively) with unity frequency near 3MHz; avoid high ESR output capacitors that can degrade stability and cause oscillations.
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Guard routing and ground planes should isolate the gate drive return path from sensitive analog grounds to prevent injection of switching noise into the error amplifier input.
Gotchas
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[Startup undervoltage lockout interaction]: Designers sometimes assume the part will always start if the supply is above 15.5V (min turn-on threshold). However, if the supply voltage is near the threshold and dips under load during startup, the device can oscillate between on and off states causing erratic output voltage and audible noise. Fix this by ensuring the supply voltage margin is at least 1V above the turn-on threshold during all startup conditions.
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[Oscillator component tolerance impact]: Using R and C components with wide tolerance or temperature coefficient can shift the oscillator frequency beyond the 58–78kHz range, causing instability or synchronization failure. The result is jittery switching waveforms and increased output ripple. Fix by selecting 1% or better tolerance resistors and temperature-stable capacitors for oscillator timing.
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[Output capacitor ESR affecting loop stability]: The internal error amplifier’s high DC gain combined with certain output capacitor ESR values can produce loop instability, seen as subharmonic oscillations or output voltage ringing. Fix by choosing low-ESR aluminum polymer or ceramic capacitors and verifying loop stability on the bench with a small-signal step.
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[Enable pin noise causing false synchronization]: Noise spikes on the enable/sync pin near the 2.6V threshold can cause unintended switching or shutdown, leading to intermittent load dropout. This may be misdiagnosed as a power supply issue. Fix by adding a small RC filter or Schmitt trigger buffer on the enable line to clean the input signal.