Key Specs
No verified spec values available.
When To Use
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3V Battery Boost → 12V @ 2A: The wide input voltage range down to 2.9V minimum and internal 7.2V regulator supply voltage make this part ideal for low-voltage battery-powered boost converters. Using a synchronous buck controller here would fail due to inability to step up from below output voltage, causing the output to never reach regulation.
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8V to 40V Input → 24V @ 1.5A: The high maximum input voltage rating of 40V with built-in current sense and a 110mV typical current limit threshold allows robust operation from automotive or industrial rails with transient tolerance. A linear regulator handling this would dissipate excessive heat and enter thermal shutdown rapidly.
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Programmable Frequency Switching from 50kHz to 1MHz: The device’s wide switching frequency range and synchronization capability starting at 50kHz enable design flexibility for optimizing noise and efficiency tradeoffs in compact power supplies. A low-frequency fixed-frequency buck controller would limit EMI control and inductor size optimization, leading to larger, noisier designs.
When Not To Use
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Battery-Powered Always-On Sensor with μA Sleep Current: Shutdown current is specified up to 6µA max, which is too high for ultra-low power applications where quiescent current dominates battery life. Use a low-IQ PFM buck instead.
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High Current Output Above 2A: Maximum output current rating of 2A makes this unsuitable for loads requiring higher continuous current. Use a multi-phase buck controller to meet the current demands and maintain thermal stability.
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Input-to-Output Voltage Differential Below 1V: The dropout voltage minimum of 7.2V internal regulator output makes this part inefficient and unstable for low differential voltage applications. Use an LDO regulator for clean regulation with low dropout and noise.
Application Notes
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The switching node (SW) has fast rising and falling edges (22ns rise, 20ns fall minimum), so keep the loop area small and use a low-inductance ground plane to minimize EMI and voltage spikes.
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the FBX pin and the VC pin are noise-sensitive error amplifier inputs; route feedback resistors and compensation components close and shield them from noisy switching nodes.
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The internal regulator (INTV) requires a minimum 4.7µF bypass capacitor; use a low-ESR X5R ceramic capacitor placed physically close to the IC’s INTVCC pin to ensure stable voltage and avoid regulator dropout.
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The shutdown/UVLO pin threshold is around 1.22V with 20mV hysteresis; ensure clean, glitch-free startup sequencing to prevent unintended shutdown during power-up.
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Synchronization input requires at least 8V clock voltage for reliable sync; lower voltages risk missed sync pulses and jitter.
Gotchas
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[INTV Undervoltage Lockout Interaction]: Designers often assume the internal 7.2V regulator is always stable, but if INTV drops below the 2.7V undervoltage lockout threshold during startup or heavy load, the IC can enter erratic switching or fail to start. Symptom is intermittent switching or no gate drive. Fix by ensuring proper INTV bypass capacitor sizing and input voltage margin, verifying regulator voltage during load transient with scope probe.
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[Sense Resistor Noise Coupling]: The low 110mV current limit threshold is sensitive to noise on the sense resistor line. Poor layout or noisy switching node coupling can cause false current limit triggering, resulting in erratic pulse skipping and output ripple. Fix by routing sense resistor traces away from SW node, using Kelvin sensing if possible, and adding a small RC filter to the sense line.
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[Minimum Off-Time Limits High Duty Cycle]: The minimum off-time of 220ns limits the maximum achievable duty cycle at high switching frequencies, especially above 500kHz. Assuming 100% duty cycle at max frequency leads to output undervoltage and instability. Fix by verifying maximum duty cycle per switching rate using the minimum off-time spec and adjusting switching frequency or output voltage accordingly.
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[Shutdown Pin Bias Current Confusion]: The shutdown input draws 2µA when low and 100nA when high, which can cause unexpected current consumption in systems that tie the pin directly to a low-power MCU or battery source without a proper pull-up/down. Symptom is excessive quiescent current or failure to enter shutdown. Fix by adding a dedicated bias resistor or buffer to the shutdown/UVLO pin to control input current precisely.