Datasheet STGAP2SICS (STMicroelectronics) - 8

STGAP2SICS Functional description 6 Functional description 6.1 Gate driving power supply and UVLO
The STGAP2SiCS is a flexible and compact gate driver with 4 A output current and rail-to-rail outputs. The device allows implementation of either unipolar or bipolar gate driving.
Figure 5. Power supply configuration for unipolar and bipolar gate driving
Unipolar gate driving Bipolar gate driving VDD VDD VDD VDD 1uF 100nF 1uF 100nF VH VH
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IN+ I 100nF 1uF IN+ I 100nF 1uF S VH VH S O GON O GON L L IN- A IN- A T GOFF T GOFF I I 1uF
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O O N VL N GNDISO GND GNDISO GND Undervoltage protection is available on VH supply pin. A fixed hysteresis sets the turn-off threshold, thus avoiding intermittent operation. When VH voltage falls below the VHoff threshold, the output buffer enters a “safe state”. When VH voltage reaches the VHon threshold, the device returns to normal operation and sets the output according to actual input pins status. The VDD and VH supply pins must be properly filtered with local bypass capacitors. The use of capacitors with different values in parallel provides both local storage for impulsive current supply and high-frequency filtering. The best filtering is obtained by using low-ESR SMT ceramic capacitors and are therefore recommended. A 100 nF ceramic capacitor must be placed as close as possible to each supply pin, and a second bypass capacitor with value in the range between 1 µF and 10 µF should be placed close to it.
6.2 Power-up, power-down and “safe state”
The following conditions define the “safe state”: • GOFF = ON state; • GON = High Impedance; • CLAMP = ON state (for STGAP2SiCSC); Such conditions are maintained at power-up of the isolated side (VH < VHon) and during whole device power down phase (VH < VHoff), regardless of the value of the input pins. The device integrates a structure which clamps the driver output to a voltage not higher than SafeClp when VH voltage is not high enough to actively turn the internal GOFF MOSFET on. If VH positive supply pin is floating or not supplied the GOFF pin is therefore clamped to a voltage smaller than SafeClp. If the supply voltage VDD of the control section of the device is not supplied, the output is put in safe state, and remains in such condition until the VDD voltage returns within operative conditions. After power-up of both isolated and low voltage sides, the device output state depends on the status of the input pins.
DS13402
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Rev 1 page 8/24
Document Outline Cover image Product status link / summary Features Application Description 1 Block diagram 2 Pin description and connection diagram 3 Electrical data 3.1 Absolute maximum ratings 3.2 Thermal data 3.3 Recommended operating conditions 4 Electrical characteristics 5 Isolation 6 Functional description 6.1 Gate driving power supply and UVLO 6.2 Power-up, power-down and “safe state” 6.3 Control inputs 6.4 Miller Clamp function 6.5 Watchdog 6.6 Thermal shutdown protection 6.7 Standby function 7 Typical application diagram 8 Layout 8.1 Layout guidelines and considerations 8.2 Layout example 9 Testing and characterization information 10 Package information 10.1 SO-8W package information 10.2 SO-8W suggested land pattern 11 Ordering information Revision history Contents List of tables List of figures