ZHCSIJ1E June 1999 – July 2018 LM2574 , LM2574HV
PRODUCTION DATA.
| PIN | I/O | DESCRIPTION | ||
|---|---|---|---|---|
| NAME | PDIP | SOIC | ||
| FB | 1 | 3 | I | Feedback sense input pin. Connect to the midpoint of feedback divider to set VOUT for ADJ version or connect this pin directly to the output capacitor for a fixed output version. |
| NC | 8, 6 | 1, 2, 7, 8, 9, 11, 13, 14 | — | No internal connection, but must be soldered to PCB for best heat transfer. |
| ON/OFF | 3 | 5 | I | Enable input to the voltage regulator. High = OFF and low = ON. Connect to GND to enable the voltage regulator. Do not leave this pin float. |
| OUTPUT | 7 | 12 | O | Emitter pin of the power transistor. This is a switching node. Attached this pin to an inductor and the cathode of the external diode. |
| PWR_GND | 4 | 6 | — | Power ground pins. Connect to system ground and SIF GND, ground pins of CIN and COUT. Path to CIN must be as short as possible. |
| SIG_GND | 2 | 4 | — | Signal ground pin. Ground reference for internal references and logic. Connect to system ground. |
| VIN | 5 | 10 | I | Supply input pin to collector pin of high-side transistor. Connect to power supply and input bypass capacitors CIN. Path from VIN pin to high frequency bypass CIN and PWR GND must be as short as possible. |