JAJSV63A August 2024 – August 2024 LM5137-Q1
ADVANCE INFORMATION
The LM5137-Q1 operates with peak current-mode control such that the compensation (COMP) voltage is proportional to the peak inductor current. During no-load or light-load conditions, the output capacitor discharges very slowly. As a result, the COMP voltage does not demand the driver output pulses on a cycle-by-cycle basis. When the LM5137-Q1 controller detects 16 missed switching cycles, the device enters sleep mode and switches to a low IQ state to reduce the current drawn from the input. For the LM5137-Q1 to go into sleep mode, the device must be programmed for diode emulation (tie PFM/SYNC to VDDA).
The typical controller IQ in sleep mode is 12.7μA with channel 1 set to 5V output and channel 2 disabled. When the LM5137-Q1 goes to sleep, PG1/2 are disabled. The nFAULT1/2 output are still active in case a fault is detected.