13892 datasheet(98/156 Pages) FREESCALE

98 / 156 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

13892

FUNCTIONAL DEVICE OPERATION

BATTERY INTERFACE AND CONTROL

If the enumeration is successful to get the stepped up current the processor will hold WDI high and continues with the

booting procedure.

• When the SPI is activated, the LPB interrupt LPBI can be cleared; other unmasked interrupts may now become active.

When leaving watchdog phase for the On mode, the interrupts will work 'normally' even if LPBI is not cleared.

• The SPI bit ACKLPB bit is set to enable the internal trickle charger. The charge LED gets activated. When the battery

crosses the BATTMIN threshold the M3.transistor is automatically closed and the battery is charged with the current not

taken by the application.

• When BP exceeds BPON, the charger state machine will successfully exit the trickle charge mode. This will make

LPBS = 0 which generates a LPBI. This interrupt will inform the processor that a full turn on is allowed. Once this

happens the application code is allowed to run full speed.

BATTERY THERMISTOR CHECK OPERATION

By default, the battery thermistor value is taken into account for charging the battery. Upon detection of a supply at

CHRGRAW, the core circuitry powers up including VCORE. As soon as VCORE is ready, the output GPO1 is made active high,

independently of the state of GPO1EN bit. The resulting voltage at ADIN5 is compared to the corresponding temperature

thresholds. If the voltage at ADIN5 is within range, the charging will behave as described thus far, however if out of range the

charger state machine will go to a wait state, pause the charge timers, and no current will be sourced to the battery. When the

temperature comes back in range, charging is continued again. The actual behavior depends on the configuration the charger

circuitry at the moment the temperature range is exceeded.

Table 80. Battery Thermistor Check Charger States

Internal precharging on a charger

M1M2 = 560 mA / SPI setting,

M3 = Open, Itrickle = 0mA

Internal precharge

Initialization

Internal precharging on USB in USB

Low Power Boot

M1M2 = 400 mA

M3 = Open, Itrickle = 0mA

Low Power Boot Precharge

Initialization

All other non fault charging modes

and configurations

M1M2 = 0 mA

M3 Closed

Initialization

The battery thermistor check can be disabled by setting the THCHKB bit. This is useful in applications where battery packs

without thermistor may be used. This bit defaults to '0', which means that initial power up only can be achieved with an already

charged battery pack or on a charger, but not on a USB Host without low power boot support. Alternatively, one can bias ADIN5

to get within the temperature window. Setting the SPI bit to disable the thermistor check will also inhibit the automatic enabling

of the GPO1 output. The GPO1 output still remains controllable through GPO1EN. As an additional feature, the charger state

machine will end up in an out of temperature state when the die temperature is below -20 °C, independent of the setting of the

THCHKB bit.

Notes:

• When using the battery charger as the only source of power, as in a battery-less application, the following precautions

should be observed:

• It is still necessary to connect ADIN5 to either VCOREDIG or a midpoint of a divider from GPIO1 to ground since the battery

charger will still interpret this voltage as the battery pack thermistor by default.

• Very careful budgeting of the total current consumption and voltage standoff from CHRGRAW to BPSNS must be made,

since the power limiter is operational by default, and a battery less system won't have a source of current if the power

dissipation limit is reached.

• If operating from a USB host the unit load limit (100 mA max.) must still be observed.

• If operating from a “wall charger”, and if there is no battery, there is an period of approximately 85 ms after RESETB is

released, but before the current limit is set to a nominal 560 mA. If the total current demand is greater than this limit, the

voltage may collapse and RESETB may pulse a few times (depending in part in the system load and dependence on

RESETB.) Therefore, at the end of this time, RESETB may or may not be active. It may be necessary to use one of the

other turn on events (such as PWRONx) to turn it back on.

Configuration

State for temperature

State for temperature back in range

out of range

ICin “On” State

IC in “Off” State

13892 データシート(PDF) 98 Page - Freescale Semiconductor, Inc

13892 データシート(HTML) 98 Page - Freescale Semiconductor, 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 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

データシートダウンロード

リンク URL

13892 データシート(PDF) 98 Page - Freescale Semiconductor, Inc

13892 データシート(HTML) 98 Page - Freescale Semiconductor, 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 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

データシート ダウンロード

リンク URL

データシートダウンロード