SLUSDC7A March   2020  – November 2020

PRODUCTION DATA

1. Features
2. Applications
3. Description
4. Revision History
5. Description (continued)
6. Device Comparison Table
7. Pin Configuration and Functions
8. Specifications
9. Detailed Description
1. 9.1 Overview
2. 9.2 Functional Block Diagram
3. 9.3 Feature Description
1. 9.3.1 Device Power Up
2. 9.3.2 Battery Charging Management
3. 9.3.3 Charging Status Indicator (STAT)
4. 9.3.4 Protections
4. 9.4 Device Functional Modes
10. 10Application and Implementation
1. 10.1 Application Information
2. 10.2 Typical Applications
1. 10.2.1 Typical Application
1. 10.2.1.1 Design Requirements
2. 10.2.1.2 Detailed Design Procedure
3. 10.2.1.3 Application Curves
2. 10.2.2 Typical Application with External Power Path
3. 10.2.3 Typical Application with MCU Programmable Charge Current
11. 11Power Supply Recommendations
12. 12Layout
13. 13Device and Documentation Support
14. 14Mechanical, Packaging, and Orderable Information

• RTE|16
• RTE|16

#### 9.3.2.6 Thermistor Temperature Monitoring

The charger device provides a single thermistor input TS pin for battery temperature monitor. RT1 and RT2 programs the cold temperature T1 and hot temperature T3. In the equations, RNTC,T1 is NTC thermistor resistance value at temperature T1 and RNTC,T3 is NTC thermistor resistance values at temperature T3. Assuming RHOT = 0, select 0°C to 45°C for battery charge temperature range, then NTC thermistor 103AT-2 resistance RNTC,T1 = 27.28 kΩ ( at 0°C) and RNTC,T3 = 4.91 kΩ (at 45°C), from the Equation 1 and Equation 2, RT1 and RT2 are derived as:

• RT1 = 4.527 kΩ

• RT2 = 23.26 kΩ

On top of the calculation results, adding RHOT resisitor can shift HOT temperature T3 up and only slightly shift up COLD temperature T1. The actual temperature T3 can be looked up in a NTC resistance table based on (RNTC,T3 - RHOT) and T1 can be looked up in a NTC resistance table based on (RNTC,T1 - RHOT). Because RNTC,T1 is much higher than RNTC,T3, RHOT can adjust HOT temperature significantly with mimimal affect on COLD temperature. RHOT is optional.

Figure 9-2 Battery Temperature Sensing Circuit
Equation 1.
Equation 2.