WM8310 datasheet(116/291 Pages) WOLFSON

116 / 291 page

WM8310

Pre-Production

PP, May 2012, Rev 3.1

116

The AUXADCIN1 monitor output current is equal to the battery charge current divided by 12500. The

battery charge current can be determined by measuring the voltage at the AUXADCIN1 pin, as

described in the following equations.

Monitor Current IM =

Charge Current IC

12500

VAUXADCIN1

Charge Current IC =

VAUXADCIN1 x 12500

10000

(assuming 10k resistor, R)

For example, a measurement of 0.72V at AUXADCIN1 would indicate that the battery charge current

is 900mA.

Note that the integrated Auxiliary ADC can be used to perform this measurement if required. In this

case, the digitised AUXADC measurement (AUX_DATA) represents the battery charge current in

accordance with the following equation.

See Section 18 for further details of the Auxiliary ADC.

17.7.6

BATTERY FAULT / OVERVOLTAGE CONDITIONS

The battery is monitored to detect an overvoltage or failure condition. These features are incorporated

to prevent malfunction of the battery charger or of the WM8310 system.

The BATT_OV_STS bit indicates if an overvoltage condition has been detected. The overvoltage

threshold is defined in Section 7.7. If a battery overvoltage condition is detected, then charging is

terminated and the CHG_OV_EINT interrupt flag is set (see Section 17.7.8).

The battery charger also detects if the battery is faulty. This is detected if the battery voltage does not

reach the fast charge threshold voltage within the defective battery timeout period (see Section 7.7),

or within a quarter of the charging time CHG_TIME (whichever is the longer time).

The battery failure condition is cleared if the battery voltage rises above the defective battery

threshold, or if any of the WM8310 power sources (including the battery) is removed and re-

connected. When the failure condition is cleared, the charger then reverts back to its initial state, and

may re-start if the conditions for charging are fulfilled.

If the battery failure condition is detected in fast charge mode, then the charger reverts to trickle

charging mode. If the fault persists, then trickle charging stops as described above.

If battery failure condition is detected, then charging is terminated and the CHG_BATT_FAIL_EINT

interrupt is set (see Section 17.7.8).

The battery overvoltage bit is defined in Table 61.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R16458

(404Ah)

Charger Status

BATT_OV_STS

Battery Overvoltage status

0 = Normal

1 = Battery Overvoltage

Table 61 Battery Overvoltage Status

WM8310 Datasheet(PDF) 116 Page - Wolfson Microelectronics plc

WM8310 Datasheet(HTML) 116 Page - Wolfson Microelectronics plc

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 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL