link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 L6981Electrical characteristicsSymbolParameterTest ConditionsMin.Typ.Max.UnitSynchronization (LNM versions only) fCLKIN (4) Synchronization range 200 500 KHz VCLKIN_TH (4) Amplitude of synchronization clock 2.3 V Synchronization pulse ON and OFF time 2.3 ≤ VCLKIN_TH ≤ 2.5 V 60 ns VCLKIN_T (4) Synchronization pulse ON and OFF time VCLKIN_TH > 2.5 V 20 ns Thermal Shutdown TSHDWN (5) Thermal shutdown temperature 165 °C T (5) HYS Thermal shutdown hysteresis 30 °C 1. Parameter tested in the static condition during testing phase. The parameter value may change over a dynamic application condition. 2. LCM version. 3. Specifications in the - 40 to 125 °C temperature range are assured by characterization and statistical correlation. 4. LNM version. 5. Not tested in production. DS13554 - Rev 1page 7/49 Document Outline 1 Diagram 2 Pin configuration 3 Typical application circuit 4 Absolute maximum ratings 5 Electrical characteristics 6 Functional description 6.1 Enable 6.2 Soft-start 6.3 Undervoltage lockout 6.4 Light-load operation 6.4.1 Low consumption mode (LCM) 6.4.2 Low noise mode (LNM) 6.4.3 Efficiency for Low consumption mode and Low noise mode part number 6.4.4 Load regulation for low consumption mode and low noise mode part number 6.5 Overvoltage protection 6.5.1 Low consumption mode part number 6.5.2 Low noise mode part number 6.6 Overcurrent protection 6.7 Thermal shutdown 7 Closing the loop 7.1 GCO(s) control to output transfer function 7.2 Error amplifier compensation network 7.3 Voltage divider 8 Design of the power components 8.1 Programmable power up threshold 8.2 External synchronization (only available for Low Noise Mode) 8.3 Output voltage adjustment 8.4 Design of the power components 8.4.1 Input capacitor selection 8.4.2 Inductor selection 8.4.3 Output capacitor selection 9 Application board 10 Efficiency curves 11 Thermal dissipation 12 Package information 12.1 SO 8L package information 13 Ordering information Revision history