Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - power monitoring Single phase, Two-phase QFN 64 Surface-mount

71M6521DE/DH/FE Data Sheet

Rev 3 Page: 51 of 107

Circuit Function

System Power

Battery Power (Non-volatile Supply)

MISSION

BROWNOUT LCD SLEEP

Yes

CE Data RAM

Yes

FIR

Yes

Analog circuits:

PLL, ADC, VREF, BME etc

Yes -- -- --

MPU clock rate

4.92MHz

(from PLL)

28.672kHz

(7/8 of 32768Hz)

-- --

MPU_DIV

Yes

ICE

Yes

DIO Pins

Yes

Watchdog Timer

Yes

LCD

Yes

EEPROM Interface (2-wire)

Yes

Yes (8kb/s)

EEPROM Interface (3-wire)

Yes

Yes (16kb/s)

UART

Yes

Optical TX modulation

Yes

Flash Read

Yes

Flash Page Erase

Yes

Flash Write

Yes

RAM Read and Write

Yes

Wakeup Timer

Yes

Oscillator and RTC

Yes

DRAM data preservation

Yes

V3P3D voltage output pin

Yes

Table 60: Available Circuit Functions (“—” means “not active”)

BROWNOUT Mode

In BROWNOUT mode, most non-metering digital functions, as shown in Table 60, are active, including ICE, UART,

EEPROM, LCD, and RTC. In BROWNOUT mode, a low bias current regulator will provide 2.5 Volts to V2P5 and

V2P5NV. The regulator has an output called BAT_OK to indicate that it has sufficient overhead. When BAT_OK = 0,

the part will enter SLEEP mode. From BROWNOUT mode, the MPU can voluntarily enter LCD or SLEEP modes.

When system power is restored, the part will automatically transition from any of the battery modes to mission mode,

once the PLL has settled.

The MPU will run at crystal clock rate in BROWNOUT. The value of MPU_DIV will be remembered (not changed) as

the part enters and exits BROWNOUT. MPU_DIV will be ignored during BROWNOUT.

While PLL_OK = 0, the I/O RAM bits ADC_E and CE_E are held in zero state disabling both ADC and CE. When

PLL_OK falls, the CE program counter is cleared immediately and all FIR processing halts. Figure 19 shows the

functional blocks active in BROWNOUT mode.