SLVS847A November 2008 – December 2016 TPS54917
PRODUCTION DATA.
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
AGND | 1 | — | Analog ground. Return for compensation network or output divider, slow-start capacitor, VBIAS capacitor, RT resistor and SYNC pin. Connect PowerPAD to AGND. |
BOOT | 5 | O | Bootstrap input. 0.022-µF to 0.1-µF low-ESR capacitor connected from BOOT to PH generates floating drive for the high-side FET driver. |
COMP | 3 | I/O | Error amplifier output. Connect frequency compensation network from COMP to VSENSE. |
PH | 6, 7, 8, 9, 10, 11, 12 | O | Phase output. Junction of the internal high-side and low-side power MOSFETs, and output inductor. |
PGND | 13, 14, 15, 16, 17, 18, 19, 20, 30, 31, 32, 33, 34 | — | Power ground. High current return for the low-side driver and power MOSFET. Connect PGND with large copper areas to the input and output supply returns, and negative terminals of the input and output capacitors. A single point connection to AGND is recommended. |
PWRGD | 4 | O | Power good open-drain output. High when VSENSE ≥ 90% Vref, otherwise PWRGD is low. Note that output is low when SS/ENA is low or internal shutdown signal active. |
RT | 29 | I | Frequency setting resistor input. Connect a resistor from RT to AGND to set the switching frequency, fs. |
SS/ENA | 27 | I/O | Slow-start/enable input or output. Dual function pin which provides logic input to enable or disable device operation and capacitor input to externally set the start-up time. |
SYNC | 28 | I | Synchronization input. Dual function pin which provides logic input to synchronize to an external oscillator or pin select between two internally set switching frequencies. When used to synchronize to an external signal, a resistor must be connected to the RT pin. |
VBIAS | 26 | O | Internal bias regulator output. Supplies regulated voltage to internal circuitry. Bypass VBIAS pin to AGND pin with a high quality, low ESR, 0.1-µF to 1-µF ceramic capacitor. |
VIN | 21, 22, 23, 24, 25 | I | Input supply for the power MOSFET switches and internal bias regulator. Bypass VIN pins to PGND pins close to device package with a high-quality, low-ESR 10-µF ceramic capacitor. |
VSENSE | 2 | I | Error amplifier inverting input. Connect to output voltage compensation network or output divider. |