Datasheet LTC3626 (Analog Devices) - 8
| Manufacturer | Analog Devices |
| Description | 20V, 2.5A Synchronous Monolithic Step-Down Regulator with Current and Temperature Monitoring |
| Pages / Page | 28 / 8 — pin FuncTions BOOST (Pin 1):. IMONIN (Pin 7):. INTV. CC (Pin 2):. IMONOUT … |
| File Format / Size | PDF / 398 Kb |
| Document Language | English |
pin FuncTions BOOST (Pin 1):. IMONIN (Pin 7):. INTV. CC (Pin 2):. IMONOUT (Pin 8):. ON (Pin 3):. TSET (Pin 4):. TRACK/SS (Pin 9):
Model Line for this Datasheet
Text Version of Document
LTC3626
pin FuncTions BOOST (Pin 1):
Boosted Floating Driver Supply Pin. The
IMONIN (Pin 7):
Average Input Current Monitor. A current (+) terminal of the external bootstrap capacitor connects proportional to the average input current flows out of this to this pin while the (–) terminal connects to the SW pin. pin. Pull this pin to INTVCC to defeat the input current moni- The normal operation voltage swing of this pin ranges tor function. An error amplifier compares the voltage on from INTVCC to PVIN + INTVCC. this pin to 1.2V (typical) and throttles the average current
INTV
as required based on the external resistor value from this
CC (Pin 2):
Internal 3.3V Regulator Output Pin. This pin should be decoupled to PGND with a low ESR ceramic pin to SGND. Selecting the external resistor value allows capacitor of value 1µF or greater. The 3.3V regulator is the user to control the maximum average input current. disabled when the RUN pin is low. See the Applications Information section for more details.
V IMONOUT (Pin 8):
Average Output Current Monitor Pin. A
ON (Pin 3):
On-Time Voltage Input. This pin sets the voltage trip point for the on-time comparator. Tying this current proportional to the average output current flows pin to the output voltage makes the on-time proportional out of this pin. Pull this pin to INTVCC to defeat the output to V current monitor function. An error amplifier compares OUT when VOUT < 6V. When VOUT > 6V, the switching frequency may become higher than the set frequency. The the voltage on this pin to 1.2V (typical) and throttles the impedance of this pin is nominally 160kΩ. average current as required based on the external resis- tor value from this pin to SGND. Selecting the external
TSET (Pin 4):
Temperature Limit Set Pin. The voltage at resistor value allows the user to control the maximum this pin determines the threshold for internal temperature average output current. See the Applications Information shutdown. When the voltage at TMON reaches the volt- section for more details. age at TSET, the LTC3626 will trigger an overtemperature fault. An overtemperature fault will initiate part shutdown,
TRACK/SS (Pin 9):
Output Voltage Tracking and Soft-Start reset soft-start and an attempt to restart once the internal Input. Forcing a voltage below 0.6V on this pin overrides the temperature falls 10°C (typical) from the threshold given at internal reference input to the error amplifier. The LTC3626 TSET. The voltage at TSET has no impact on a secondary will servo the FB pin to the TRACK/SS voltage under this overtemperature shutdown threshold within the LTC3626 condition. Above 0.6V, the tracking function stops and the as described in Note 4 of the Electrical Characteristics internal reference resumes control of the error amplifier. An section. internal 1.4µA (typical) pull-up current from INTVCC allows a soft-start function to be implemented by connecting an
TMON (Pin 5):
Temperature Monitor Output. A voltage external capacitor between this pin and ground. See the proportional to the measured on-die temperature will ap- Applications Information section for more details. pear at this pin. The voltage-to-temperature scaling factor is 200°K/V. See the Applications Information section for
FB (Pin 10):
Output Voltage Feedback. This pin is the input detailed information on the TMON function. Tie this pin to to the error amplifier that compares the feedback voltage INTV to the internal 0.6V reference voltage. Connect this pin to CC to disable the temperature monitor circuit. the appropriate resistor divider network to program the
SGND (Pin 6):
Signal Ground Pin. This pin should have a desired output voltage. low noise connection to reference ground. The feedback resistor network, external compensation network, current monitor components, and RT resistor should be connected to this ground. 3626fa 8 For more information www.linear.com/LTC3626 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
pin FuncTions BOOST (Pin 1):
Boosted Floating Driver Supply Pin. The
IMONIN (Pin 7):
Average Input Current Monitor. A current (+) terminal of the external bootstrap capacitor connects proportional to the average input current flows out of this to this pin while the (–) terminal connects to the SW pin. pin. Pull this pin to INTVCC to defeat the input current moni- The normal operation voltage swing of this pin ranges tor function. An error amplifier compares the voltage on from INTVCC to PVIN + INTVCC. this pin to 1.2V (typical) and throttles the average current
INTV
as required based on the external resistor value from this
CC (Pin 2):
Internal 3.3V Regulator Output Pin. This pin should be decoupled to PGND with a low ESR ceramic pin to SGND. Selecting the external resistor value allows capacitor of value 1µF or greater. The 3.3V regulator is the user to control the maximum average input current. disabled when the RUN pin is low. See the Applications Information section for more details.
V IMONOUT (Pin 8):
Average Output Current Monitor Pin. A
ON (Pin 3):
On-Time Voltage Input. This pin sets the voltage trip point for the on-time comparator. Tying this current proportional to the average output current flows pin to the output voltage makes the on-time proportional out of this pin. Pull this pin to INTVCC to defeat the output to V current monitor function. An error amplifier compares OUT when VOUT < 6V. When VOUT > 6V, the switching frequency may become higher than the set frequency. The the voltage on this pin to 1.2V (typical) and throttles the impedance of this pin is nominally 160kΩ. average current as required based on the external resis- tor value from this pin to SGND. Selecting the external
TSET (Pin 4):
Temperature Limit Set Pin. The voltage at resistor value allows the user to control the maximum this pin determines the threshold for internal temperature average output current. See the Applications Information shutdown. When the voltage at TMON reaches the volt- section for more details. age at TSET, the LTC3626 will trigger an overtemperature fault. An overtemperature fault will initiate part shutdown,
TRACK/SS (Pin 9):
Output Voltage Tracking and Soft-Start reset soft-start and an attempt to restart once the internal Input. Forcing a voltage below 0.6V on this pin overrides the temperature falls 10°C (typical) from the threshold given at internal reference input to the error amplifier. The LTC3626 TSET. The voltage at TSET has no impact on a secondary will servo the FB pin to the TRACK/SS voltage under this overtemperature shutdown threshold within the LTC3626 condition. Above 0.6V, the tracking function stops and the as described in Note 4 of the Electrical Characteristics internal reference resumes control of the error amplifier. An section. internal 1.4µA (typical) pull-up current from INTVCC allows a soft-start function to be implemented by connecting an
TMON (Pin 5):
Temperature Monitor Output. A voltage external capacitor between this pin and ground. See the proportional to the measured on-die temperature will ap- Applications Information section for more details. pear at this pin. The voltage-to-temperature scaling factor is 200°K/V. See the Applications Information section for
FB (Pin 10):
Output Voltage Feedback. This pin is the input detailed information on the TMON function. Tie this pin to to the error amplifier that compares the feedback voltage INTV to the internal 0.6V reference voltage. Connect this pin to CC to disable the temperature monitor circuit. the appropriate resistor divider network to program the
SGND (Pin 6):
Signal Ground Pin. This pin should have a desired output voltage. low noise connection to reference ground. The feedback resistor network, external compensation network, current monitor components, and RT resistor should be connected to this ground. 3626fa 8 For more information www.linear.com/LTC3626 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
