Boost Module with True Shutdown

MAXM17225

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Figure 1 and Figure 2 show typical waveforms while in each mode. ULPM is used when the system is in standby or an

ultra-low-power state. LPM and HPM are useful for sensitive sensor measurements or during wireless communications

for medium output currents and large output currents, respectively. The user can calculate the value of the load current

ULPM to LPM transition current happens at approximately 3.28mA. The MAXM17225 enters HPM when the inductor

current transitions from DCM to CCM.

= (300ns x 300ns / 2 x 1µH) x [1.5V/{(3V/1.5V)-1}] x (0.85/17.5µs) = 3.28mA

VOUT TARGET

VOUT TARGET - LOAD REG

VOUT TARGET + 2.5%

ULTRA-LOW-POWER MODE (ULPM): LIGHT LOADS

HIGH-POWER MODE (HPM): HEAVY LOADS

TIME

LOAD DEPENDENT

LOW-POWER MODE (LPM): MEDIUM LOADS

CCM

DCM

DCM

17.5us

750ns

5us

Figure 1. ULPM, LPM, and HPM waveforms

VOUT TARGET

VOUT TARGET - LOAD REG

VOUT TARGET + 2.5%

ULTRA-LOW-POWER MODE (ULPM): LIGHT LOADS

HIGH-POWER MODE (HPM): HEAVY LOADS

TIME

LOAD DEPENDENT

LOW-POWER MODE (LPM): MEDIUM LOADS

CCM

DCM

DCM

17.5us

650ns

100ms

7us

Figure 2. ULPM, LPM, and HPM waveforms