Datasheet STGAP2HD (STMicroelectronics) - 9

STGAP2HD Functional description 6 Functional description 6.1 Gate driving power supply and UVLO
The STGAP2HD is a flexible and compact gate driver with 4 A output current and rail-to-rail outputs. The device allows to implement either unipolar or bipolar gate driving.
Figure 3. Power supply configuration for unipolar and bipolar gate driving
Unipolar gate driving Bipolar gate driving VH_A VH_A VDD VDD GON_A VH GON_A VH GOFF_A GOFF_A INA INA CLAMP_A CLAMP_A VL GNDISO_A
I
GNDISO_A
I
INB
S
INB
S O O
Control
L
Control
L A A
VH_B Logic VH_B Logic
T
BRAKE
T
BRAKE
I I O O
GON_B VH GON_B VH
N N
GOFF_B GOFF_B SD SD CLAMP_B CLAMP_B iLOCK VL iLOCK GNDISO_B GNDISO_B GND GND Undervoltage protection is available on VH_x supply pin. A fixed hysteresis sets the turn-off threshold, thus avoiding intermittent operation. When VH_x voltage goes below the VHoff threshold, the output buffer goes into “safe state”. When VH_x 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_x 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, which 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 Such conditions are maintained at power-up of the isolated side (VH_x < 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_x 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 side the device output state depends on the input pins' status.
DS13652
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Rev 1 page 9/23
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 Watchdog 6.5 Thermal shutdown protection 6.6 Standby function 6.7 Interlocking 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-36W package information 11 Suggested land pattern 12 Ordering information Revision history Contents List of tables List of figures