- AEC-Q100 Qualified for Automotive Applications:
- Device Temperature Grade 1: –40°C to +125°C Ambient OperatingTemperature
- Versatile Synchronous Buck DC/DC Controller
- Wide Input Voltage Range of 3.5 V to 65V
- 1% Accurate, Fixed 3.3-V, 5-V orAdjustable Outputs from 0.6 V to 55 V
- Shutdown Mode Current: 4 µA Typical
- No-LoadStandby Current: 15 µA Typical
- Two Interleaved Synchronous Buck Channels
- Dual-Channel or Single-OutputMulti-Phase
- 65-ns tON(min) for HighVIN / VOUT Ratio
- 60-nstOFF(min) for LowDropout
- Switching Frequency From 100 kHz to 2.2 MHz
- SYNC In and SYNC Out Capability
- OptionalSpread-Spectrum Modulation
- Meets CISPR 25 EMIRequirements
- Inherent Protection Features for Robust Design
- Hiccup-Mode Overcurrent Protection
- IndependentENABLE and PGOOD Functions
- VCC, VDDA, and Gate-Drive UVLOProtection
- Thermal Shutdown Protection WithHysteresis
- Slew-Rate-Controlled Adaptive Gate Drivers
- Selectable Diode Emulation or FPWM
- VQFN-40 Package With Wettable Flanks
- Create a Custom Design Using the LM5143-Q1 With WEBENCH® Power Designer
All trademarks are the property of their respective owners.
The LM5143-Q1 is a65-V synchronous buck DC/DCcontroller for high-current single or dual outputs. The device uses an interleaved, stackable,current-mode control architecture for easy loop compensation, fast transient response, excellentload and line regulation, and accurate current sharing with paralleled phases for higher outputcurrent. A high-side switch minimum on-time of 65 ns gives large step-down ratios, enabling thedirect conversion from 12-V, 24-V, or
48-V automotive inputs to low-voltage railsfor reduced system complexity and solution cost. The LM5143-Q1 continues to operate during input voltage dips as low as 3.5 V,at nearly 100% duty cycle if needed.
Current is sensed using the inductor DCR for highest efficiency or an optional shuntresistor for high accuracy. The 15-µA no-load quiescent current with the output voltage inregulation extends operating run-time in battery-powered systems. Power the LM5143-Q1 from the output of theswitching regulator or another available source for even lower input quiescent current and powerloss.
Several features are included to simplify compliance with CISPR 25 and automotive EMIrequirements. Adaptively timed, high-current MOSFET gate drivers with adjustable slew rate controlminimize body diode conduction during switching transitions, reducing switching losses andimproving thermal and EMI performance at high input voltage and high switching frequency. To reduceinput capacitor ripple current and EMI filter size, 180° interleaved operation is provided for twooutputs. A 90° out-of-phase clock output works well for cascaded, multi-channel, or multi-phasepower stages. Resistor-adjustable switching frequency as high as 2.2 MHz can be synchronized to anexternal clock source to eliminate beat frequencies in noise-sensitive applications. Optionalspread spectrum modulation further improves the EMI signature.
Additional features of the LM5143-Q1 include user-selectable diode emulation for lower currentconsumption at light-load conditions, configurable soft-start functions, open-drain Power-Goodflags for fault reporting and output monitoring, independent enable inputs, monotonic start-up intoprebiased loads, integrated VCC bias supply regulator, programmable hiccup-mode overloadprotection, and thermal shutdown protection with automatic recovery.
The LM5143-Q1controller comes in a 6-mm × 6-mm thermally-enhanced, 40-pin VQFN package with wettable flanks tofacilitate optical inspection during manufacturing.