Datasheet LTM4691 (Analog Devices) - 7

LTM4691
PIN FUNCTIONS PACKAGE ROW AND COLUMN LABELING MAY VARY RUN1 (B3), RUN2 (B2):
Run Control Input of Each
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
Switching Mode Regulator Channel. It has a precision
LAYOUT CAREFULLY.
threshold and an optional external resistor divider from
V
V
IN (C4, C1):
Power Input Pins. Both VIN pins are inter- IN or another supply programs when each channel is nally connected and must be connected with a short. enabled. If the precision threshold is not required, drive Each V RUN1, RUN2 to V IN should have its own input bypass capacitors. IN to enable. Do Not Float. Recommend placing input decoupling capacitors as close
FB1 (A3), FB2 (A2):
The Negative Input of the Error as possible to the pins. Amplifier for the switching Mode Regulator Channel. The
V
LTM4691 regulates the voltage between FB and SGND
OUT1 (E4, F3, F4), VOUT2 (E1, F1, F2):
Power Output Pins of Each Switching Mode Regulator. Apply output load to 500mV. A resistor divider connecting to VOUT sets the between these pins and GND pins. Recommend placing output voltage. output decoupling capacitance directly between these
MODE/SYNC (B4):
Mode Selection and External Clock pins and GND pins. Synchronization Input. Ground this pin to enable pulse-
GND (C2, C3, D1, D2, D3, D4, E2, E3):
Power Ground skipping mode. For higher efficiency at light loads, tie Pins for Both Input and Output Returns. this pin to VIN to enable Burst Mode. For fast transient response and constant frequency operation over a wide
SGND1 (A4), SGND2 (A1):
Signal Ground Connection load range, float this pin to enable forced continuous
PGOOD (B1):
Power Good Output. Open-drain output. mode. Drive MODE/SYNC with an external clock to syn- When the regulated output voltage of either switching chronize both buck converters to the applied frequency. regulator falls below its PGOOD threshold or rises above When syncing, the operating mode is forced continuous. its overvoltage threshold, this pin is driven low. The slope compensation is automatically adapted to the external clock frequency. In the absence of an external clock both buck converters will switch at the default switching frequency. Rev. 0 For more information www.analog.com 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Decoupling Requirements Operation Applications Information VIN to VOUT Step-Down Ratios Output Voltage Programming Input Decoupling Capacitors Output Decoupling Capacitors Mode Selection Operating Frequency and External Synchronization Power GOOD Output Overvoltage Protection Output Voltage Soft-Start Dropout Operation Output Short-Circuit Protection and Recovery Load Sharing Using the Precision RUN Threshold Thermal Considerations and Output Current Derating Safety Considerations Layout Checklist/Example Applications Information Typical Applications Pin Configuration Table LTM4691 Component LGA Pinout Package Description Package Photo Related Parts