ACT4911 datasheet(24/33 Pages) QORVO

24 / 33 page

Data Sheet Rev. C, August 2021 | Subject to change without notice

24 of 33

www.qorvo.com

ACT4911

Power Loss Protection with 6A eFuse

SCALE_HCHK _2X and SCALE_HCHK _4X in register

0x27h [1:0].

The ACT4911 allows for very flexible health checking

routines by allowing the system to manually enable the

10mA

discharge

current

setting

the

EN_STR10mASINK bit = 1. In this situation, the system

manually turns the discharge current on and off. The

storage capacitor voltage threshold is still determined

by the HMON_THR register. This function is useful for

checking extremely large capacitor values which need

very long discharge times.

PG_THR

(Programmable)

VSTR

Initial Charge Health Testing

Top-Off

Maintain

10mA

50mA

200us

Programmable

Discharge Time

Programmable

Interval Time

Storage CapVoltage

Discharge Current

Figure 6: Storage Voltage at Different Stages

The register HMON_TSET [3:0] sets the health check

discharge time as shown in Table 7. This also allows the

use of the ADC to check the slope of the discharge and

calculate the capacitance.

Table 7: Health Check Discharge Time

HMON_TSET[2:0]

HMON_TSET[3] (ms)

000

384

001

512

010

640

011

768

100

896

101

1024

110

128

1152

111

256

1280

ADC MONITORING

General Description

The ACT4911 contains a built-in analog to digital

converter, ADC, which can be used to monitor five

system level parameters. These include input voltage,

output voltage, storage capacitor voltage, eFuse current,

and die temperature. It is a single 8 bit delta-sigma ADC

that uses an analog input multiplexer to select one of six

channels for the A/D conversion. The resulting digital

results are stored in six digital registers. A six to one

multiplexer connects one of the ADC output registers to

the user accessible register map.

ADC Configuration

The ACT4911 ADC is configured through the I2C

interface. It is enabled and disabled by the EN_ADC

manual single-shot conversion and automatic polling

conversion.

Single-Shot Conversion

Configure the IC for single-shot conversion mode by

setting the following I2C bits in register 0x08h

ADC_ONE_SHOT = 1.

ADC_CH_SCAN = 0

EN_ADCBUF = 1

In single shot mode, the user defines the input channel

to be converted and then manually initiates the ADC

conversion. I2C bits ADC_CH_CONV [2:0] in register

0x08h select the input channel to be converted.

ADC_CH_READ [2:0] selects the ADC channel to be

read. These should be set to the same channel. The

user initiates an ADC read by writing a 1 into EN_ADC

in register 0x08h. When ADC conversion is complete,

the ADC_DATA_READY bit (register 0x07h [7]) is set to

1, nIRQ is asserted low, and EN_ADC automatically

changes back to 0. The uP can then read the status bits

to find that the ADC conversion is complete. The ADC

data are stored in ADC_DOUT [13:6] in register 0x05h.

nIRQ stays asserted low and the ADC_READY_BIT

stays equal to 1 until the ADC data is read. Reading the

ADC data automatically deasserts nIRQ. To initiate

another ADC conversion for the same channel, set

EN_ADC=1. To initiate an ADC conversion for another

channel,

change

ADC_CH_CONV

and

ADC_CH_READ to the appropriate channel and then

set EN_ADC=1.

ACT4911 Datasheet(PDF) 24 Page - Qorvo, Inc

ACT4911 Datasheet(HTML) 24 Page - Qorvo, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Datasheet Download

Link URL