Datasheet LTM4649 (Analog Devices) - 7

LTM4649
PIN FUNCTIONS PACKAGE ROW AND COLUMN LABELING MAY VARY PGOOD (C7):
Output Voltage Power Good Indicator. Open-
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
drain logic output that is pulled to ground when the output
LAYOUT CAREFULLY.
voltage is not within ±10% of the regulation point.
GND (A1-A5, A7-A11, B1, B9-B11, E1, F3, F5, G1-G7): V
Ground Pins for Both Input and Output Returns. All ground
OUT_LCL (G9):
This pin is connected to the top of the internal top feedback resistor for the output. When the pins need to connect with large copper areas underneath remote sense amplifier is used, connect the remote sense the unit. amplifier output DIFFOUT to VOUT_LCL to drive the 10k top
TEMP (A6):
Onboard Temperature Diode for Monitoring feedback resistor. When the remote sense amplifier is not the VBE Junction Voltage Change with Temperature. See used, connect VOUT_LCL to VOUT directly. the Applications Information section.
FREQ (E3):
Frequency Set Pin. A 10µA current is sourced
CLKIN (B3):
External Synchronization Input to Phase De- from this pin. A resistor from this pin to ground sets a tector Pin. A clock on this pin will enable synchronization voltage, that in turn, programs the operating frequency. with forced continuous operation. See the Applications Alternatively, this pin can be driven with a DC voltage that Information section. can set the operating frequency. See the Applications In-
PHMODE (B4):
This pin can be tied to GND, tied to INTV formation section. The LTM4649 has an internal resistor CC or left floating. This pin determines the relative phases to program the frequency to 450kHz. between the internal controllers and the phasing of the
TRACK/SS (E5):
Output Voltage Tracking Pin and Soft- CLKOUT signal. See Table 2 in the Operation section. Start Inputs. The pin has a 1.2µA pull-up current source.
MODE (B5):
Mode Select Input. Connect this pin to A capacitor from this pin to ground will set a soft-start INTV ramp rate. In tracking, the regulator output can be tracked CC to enable Burst Mode operation. Connect to ground to enable forced continuous mode of operation. Floating to a different voltage. The different voltage is applied to this pin will enable pulse-skipping mode. a voltage divider then the slave output’s track pin. This voltage divider is equal to the slave output’s feedback
NC (B7-B8, C3-C4):
No Connection Pins. Either float these divider for coincidental tracking. See the Applications pins or connect them to GND for thermal purpose. Information section.
VIN (C1, C8, C9, D1, D3-D5, D7-D9 and E8):
Power Input
VFB (E7):
The Negative Input of the Error Amplifier. Inter- Pins. Apply input voltage between these pins and GND nally, this pin is connected to VOUT_LCL with a 10k precision pins. Recommend placing input decoupling capacitance resistor. Different output voltages can be programmed directly between VIN pins and GND pins. with an additional resistor between VFB and ground pins.
V
In PolyPhase operation, tying the V
OUT (C10-C11, D10-D11, E9-E11, F9-F11, G10-G11):
FB pins together allows Power Output Pins. Apply output load between these pins for parallel operation. See the Applications Information and GND pins. Recommend placing output decoupling section for details. capacitance directly between these pins and GND pins.
RUN (F1):
Run Control Pin. A voltage above 1.25V will turn
SW (C5):
Switching Node of the Circuit. This pin is used on the module. The RUN pin has a 1µA pull-up current, to check the switching frequency. Leave pin floating. A and then once the RUN pin reaches 1.2V an additional resistor-capacitor snubber can be placed from SW to GND 4.5µA pull-up current is added to this pin. to eliminate high frequency switch node ringing. See the Applications Information section. 4649fc For more information www.linear.com/LTM4649 7 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Package Photo Revision History Typical Application Design Resources Related Parts