- Two synchronous step-down regulators
- 180° out-of-phase operation
- Fixed nominal frequency of 200 kHz: LM5642
- Fixed nominal frequency of 375 kHz: LM5642X
- Synchronous switching frequencies from 150 kHz to 250 kHz are LM5642X LM5642 and 200 kHz to 500 kHz
- 4.5V to 36V input range
- 50μA shutdown current
- Adjustable output 1.3V to 90% of input voltage
- 0.04% (typical) line and load regulation accuracy
- With or without detection resistive current mode control
- Separate enable/soft-start pins allow for simple sequential start configuration.
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Configurable to operate in parallel with a single output. (See.) ）
- Adjustable cycle-by-cycle current limit
- Enter the undervoltage lock
- Output overvoltage latching protection
- Output undervoltage protection and delay
- Thermal shutdown
- When self-discharge output capacitors, the voltage regulator is turned off
- TSSOP and eTSSOP (exposed PAD) packages
illustrate
The LM5642 series includes two current-mode synchronous step-down regulator controllers operating 180° phase with each other, the LM5642 and the LM5642X switching at 375kHz at 200kHz normal.
Out-of-phase operation reduces the input ripple current RMS, which greatly reduces the input capacitance required. The switching frequency can be synchronized to the LM5642 between 150 kHz and the LM5642X kHz external clock between 250 kHz and 200 kHz and 500. The two switching regulator outputs can also be connected in parallel to act as a dual-phase single-output regulator.
The output of each channel can be independently regulated from 1.3V to 90% of the input voltage. An internal 5V power supply can also be used to drive an external bootstrap circuit.
Current-mode feedback control ensures excellent line and load regulation and excellent load transient response fast and wide loop bandwidth. Currently, both in the pre-detection VDS FET or across external current detection resistors are connected in series with the FET drain.
The LM5642 function simulates a soft-start circuit, which is the output load, making soft-start behavior more predictable than traditional soft-start circuits that control output capacitance-independent.
Overvoltage protection is two outputs. A UV delay pin can also allow for a delayed shutdown time for the IC based on the output voltage event.
apply
- Embedded computer systems
- navigation system
- Communication system
- Stb
- WebPAD
- Point-of-load power architecture
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