- Two synchronous buck 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 from 1.3V to 90% of Input Voltage
- 0.04% (typical) line and load regulation accuracy
- With or without sense resistor current mode control
- A separate enable/soft-start pin allows for simple sequential startup configuration.
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Can be configured for single-output parallel operation. (See.) ）
- Adjustable cycle-by-cycle current limit
- Input undervoltage lockout
- Output overvoltage lockout protection
- Output undervoltage protection and delay
- Thermal shutdown
- When the self-discharging output capacitor is performed, the regulator is turned off
- TSSOP and eTSSOP (Exposed PAD) packages
illustrate
The LM5642 series consists of two current-mode synchronous step-down regulator controllers operating the LM5642 with 180° phase of each other and the LM5642X at a switching frequency of 200kHz at 375kHz.
Out-of-phase operation reduces input ripple current rms, greatly reducing the required input capacitance. The switching frequency can be synchronized to the LM5642X external clock between 150 kHz and the LM5642X kHz 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. The internal 5V supply can also be used to drive an external bootstrap circuit.
Current-mode feedback control guarantees excellent line and load regulation and excellent load transient response with fast wide loop bandwidth. Currently, either the VDS FET before sensing or across external current sense resistors are connected in series with the top of the FET drain.
The LM5642 features analog soft-start circuitry, which is the output load, making soft-start behavior more predictable, independent of the output capacitance controlled than traditional soft-start circuits.
Overvoltage protection is two outputs. An UV delay pin also allows the IC to delay the off-time based on the voltage event output.
apply
- Embedded computer systems
- Navigation system
- Communication systems
- Stb
- WebPAD
- Point-of-load power architecture
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