SNVSCR9A October 2024 – December 2024 LM61480T-Q1 , LM61495T-Q1
PRODUCTION DATA
PIN | TYPE(1) | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
PGND2 | 1 | G | Power ground to internal low-side MOSFET. Connect to system ground. Low-impedance connection must be provided to PGND1. Connect a high-quality bypass capacitor or capacitors from this pin to VIN2. |
VIN2 | 2 | P | Input supply to the regulator. Connect a high-quality bypass capacitor or capacitors from this pin to PGND2. Provide a low-impedance connection to VIN1. |
RBOOT | 3 | P | Connect to CBOOT through a resistor. A resistance, typically between 0Ω and 100Ω, is used to adjust the slew rate of the SW node rise time. See Figure 7-10. |
CBOOT | 4 | P | High-side driver upper supply rail. Connect a 100nF capacitor between the SW pin and CBOOT. An internal diode charges the capacitor while SW node is low. |
BIAS | 5 | P | Input to internal voltage regulator. Connect the pin to an output voltage point or an external bias supply from 3.3V to 12V. Connect an optional high-quality 0.1µF capacitor from this pin to GND for the best performance. If output voltage is above 12V and no external supply is used, tie the pin to ground. |
VCC | 6 | O | Internal regulator output. Used as supply to internal control circuits. Do not connect this pin to any external loads. Connect a high-quality 1µF capacitor from this pin to AGND. |
FB | 7 | I | Feedback input to regulator. Connect this pin to a feedback divider tap point. Do not float or ground. |
AGND | 8 | G | Analog ground for regulator and system. All electrical parameters are measured with respect to this pin. Connect this pin to PGND1 and PGND2 on PCB. |
RT | 9 | I/O | Connect this pin to ground through a resistor with a value between 6.8kΩ and 80kΩ to set the switching frequency between 200kHz and 2200kHz. Connect to VCC for 400kHz. Connect to GND for 2.2MHz. Do not float. |
RESET | 10 | O | Open-drain RESET output. Connect to a suitable voltage supply through a current limiting resistor. High = power OK, low = fault. RESET goes low when EN = low. |
SPSP | 11 | I | Connect to GND to disable spread spectrum. Connect to VCC or through a resistor to ground to enable spread spectrum. If using spread spectrum, a VCC connection turns off the spread spectrum tone correction while a resistor to ground adjusts the tone correction to lower the output voltage ripple. Do not float this pin. See Section 7.3.10. |
SYNC/MODE | 12 | I | This pin controls the mode of
operation of the LM614xxT-Q1. Modes include Auto mode
(automatic PFM/PWM operation), forced pulse width
modulation (FPWM), and synchronized to an external
clock. The clock triggers on the rising edge of an
applied external clock. Pull low to enable Auto
mode of operation, pull high to enable FPWM, or
connect to a clock to synchronize to an external
frequency in FPWM mode. Do not float this pin. When synchronized to an external clock, use the RT pin to set the internal frequency close to the synchronized frequency to avoid disturbances if the external clock is turned on and off. |
EN | 13 | I | Precision enable input to regulator. High = on, low = off. Can be connected to VIN. Precision enable allows the pin to be used as an adjustable UVLO. Do not float. See Section 7.3.2. |
VIN1 | 14 | P | Input supply to the regulator. Connect a high-quality bypass capacitor or capacitors from this pin to PGND1. Low-impedance connection must be provided to VIN2. |
PGND1 | 15 | G | Power ground to internal low-side MOSFET. Connect to system ground. Low-impedance connection must be provided to PGND2. Connect a high-quality bypass capacitor or capacitors from this pin to VIN1. |
SW | 16 | P | Switch node of the regulator. Connect to the output inductor. |