TSM108 VOLTAGE AND CURRENT STEPDOWN PWM CONTROLLER OUTPUT HIGH SIDE CURRENT SENSING APPLICATION DIAGRAM PRECISE CC/CV REGULATION ADJUSTABLE SWITCHING FREQUENCY ADJUSTABLE OVP/UVP UVLO THRESHOLDS STANDBY MODE FEATURE SUSTAINS 60V MINIMAL EXTERNAL COMPONENTS COUNT DRIVES EXTERNAL P-CHANNEL MOSFET OR PNP BIPOLAR TRANSISTORS DESCRIPTION D SO14 TSM108 is a step-down PWM controller designed (Plastic Micropackage) to drive an external P-channel MOSFET, provid- ing constant voltage and constant current regula- ORDER CODE tions in battery charger applications. Package TSM108 can easily be configured for very wide Part Number Temperature Range D voltage and current needs. TSM108I -40, +125C It has been realized in rugged BCD technology D = Small Outline Package (SO) - also available in Tape & Reel (DT) and includes a PWM generator, Voltage and Cur- rent control loops, a precise Voltage Reference, PIN CONNECTIONS (top view) and a Gate Driver. The device can sustain 60V on Vcc, and therefore meet the standard Load Dump requirements of the 12V cars battery. VCC 1 14 GD On boards there are other security functions which STBY 2 13 VS lock the external power in OFF state: OVLO (Over Voltage Lockout) and UVLO (Under Voltage Lock- GND 3 12 ICTRL out). The mosfet gate is also protected from over UV 4 11 VCTRL voltage drive thanks to a 12V clamping protection circuit. OV 5 10 VREF Moreover, a standby feature allows very low qui- G 6 9 ICOMP escent current when activated, but keeping safe the external power element when Off. OSC 7 8 VCOMP The IC is suitable for 12V car accessories, as well as other DC/DC step down converters. March 2006 1/13TSM108 PIN DESCRIPTION Name Pin Description VCC 1 Supply voltage of both the signal part and the gate drive STBY 2 Standby Command when Low, the device goes in standby GND 3 Ground. Current return for both the gate drive and quiescent currents UV 4 Programmable Under Voltage Lockout. Preset value is 8V min OV 5 Programmable Over Voltage Lockout. Preset value is 33V max G 6 Internally Connected to Ground OSC 7 Oscillator pin to set operating frequency via external capacitor VCOMP 8 Error amplifier output of voltage loop ICOMP 9 Error amplifier output of current loop VREF 10 2,52V Voltage Reference VCTRL 11 Error amplifier of voltage loop, non inverting ICTRL 12 Error amplifier of current loop inverting input VS 13 Current sense Input GD 14 Totem pole gate driver for external P-channel MOSFET ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V Supply Voltage - Transient conditions (400ms max.) 60 V CC T Maximum Junction Temperature 150 C j R Thermal Resistance Junction to Ambient (SO package) 130 C/W thja T Storage Temperature -55 to +125 C stg V Out Terminal Voltage (ICTRL, VS) 10 V max OPERATING CONDITIONS Symbol Parameter Value Unit V Supply Voltage UVLO to OVLO V CC Vter1 Out Terminal Voltage (ICTRL, VS) 0 to 9 V Out Terminal Voltage (UV, OV, OSC) 0 to 6 V Vter2 2/13