LTC4099 datasheet(40/52 Pages) LINER

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LTC4155

4155fc

Table 34. Input Undervoltage Current Limit (Brownout

Detection) Interrupt Mask

INPUT UNDERVOLTAGE CURRENT LIMIT (BROWNOUT

DETECTION) INTERRUPT MASK

REG6

SUB ADDRESS

0x06

ENABLE_INPUT_UVCL_INT

DIRECTION

Write and Readback

INTERRUPT ENABLE

STATUS

Input Undervoltage

Current Limit

Interrupts Disabled*

Input Undervoltage

Current Limit

Interrupts Enabled

*Default.

Interrupt triggered by any change in INPUT_UVCL_ACTIVE. Any data

written to sub address 0x06 has side effect of clearing any pending

interrupt request.

APPLICATIONS INFORMATION

Figure 9. Alternate NTC Bias Network

Alternate NTC Thermistors and Biasing

The LTC4155 provides temperature qualified charging if a

grounded thermistor and a bias resistor are connected to the

NTC pin. Charging is paused if the temperature rises above

an NTC_TOO_HOT limit or falls below an NTC_TOO_COLD

limit. By using a Vishay curve 2 thermistor and a bias resis-

tor whose value is equal to the room temperature resistance

of the thermistor (r25), the upper and lower tempera-

tures are preprogrammed to approximately 40°C and

0°C, respectively. The NTC_HOT_FAULT threshold which

optionally generates an interrupt and/or enables the

overtemperature battery conditioner is preprogrammed

to approximately 60°C.

With minor modifications to the thermistor bias network

as shown in Figure 9, it is possible to adjust either one or

two of the three temperature thresholds with the constraint

that it is usually not possible to move the temperature

thresholds closer together. Intuitively, this would require

increased temperature sensitivity from the thermistor.

OPERATION

In the explanation below, the following notation is used.

r25

NTC thermistor value at 25°C.

RBIAS

Low drift bias resistor, connected between the

NTCBIAS and NTC pins.

Table 35. USB On-The-Go Step-Up Voltage Converter

Manual Activation

USB On-The-Go STEP-UP VOLTAGE CONVERTER MANUAL

ACTIVATION

REG6

SUB ADDRESS

0x06

REQUEST_OTG

DIRECTION

Write and Readback

STEP-UP

REGULATOR

ACTIVATION

Step-Up Regulator

Activation Auto-

matic or Disabled*

Enable Step-Up

Voltage Regulator

*Default.

Regulator cannot be activated if voltage is applied to either the USB or

WALL inputs. Automatic activation controlled by LOCKOUT_ID_PIN. Any

data written to sub address 0x06 has side effect of clearing any pending

interrupt request.

RNTC

RBIAS

LTC4155

4155 F09

NTC

NTCBIAS

RTEMP_RANGE

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