Datasheet LTM4645 (Analog Devices) - 7

LTM4645
pin FuncTions PACKAGE ROW AND COLUMN LABELING MAY VARY
external supply 4.5V or above through a 2.2Ω plus 1µF
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
R-C filter. See the Application Information section.
LAYOUT CAREFULLY. INTV V CC (C6):
Internal 5.5V LDO for driving the control
IN (A1-A3, B1-B2, C1-C2):
Power Input Pins. Apply input circuitry decouple with pin to GND with a minimum of voltage between these pins and GND pins. Recommend 2.2µF low ESR ceramic capacitor. The 5.5V LDO has a placing input decoupling capacitance directly between VIN 50mA current limit. pins and GND pins.
PHASMD (C7):
This pin determines the relative phases
GND (A4, A7, B3, C3, C4, D1-D4, E2-E4, F2, F4, F6, G1-
between the internal controller and the CLKOUT signal.
G4, H1-H5, J5-J7, K5-K7):
Ground Pins for Both Input See Table 2 in the Application Information section. and Output Returns. All ground pins need to connect with large copper areas underneath the unit.
FREQ (D7):
Frequency Set Pin. A 20µA current is sourced from this pin. A resistor from this pin to ground sets a
RUN (A6):
Run Control Pin. A voltage above 1.35V will voltage that in turn programs the operating frequency. turn on the module. This is a 1µA pull-up current on this Alternatively, this pin can be driven with a DC voltage pin. Once the RUN pin rises above the 1.35V threshold that can set the operating frequency. See the Applications the pull-up current increases to 5µA. Information section.
PWM (B4):
Control PWM Three-State Output Signal. For
HIZB (E5):
Phase Shedding Input Pin. When this pin is low, monitor and test purpose only. Do not drive this pin. TRACK/SS, COMP and PWM pin go to high impedance.
CLKOUT (B5):
Clock output with phase control using the Tie to INTVCC or VIN to disable this function. PHASMD pin to enable multiphase operation between
V
devices. See the Applications Information section.
FB (E6):
The Negative Input of the Error Amplifier. Inter- nally, this pin is connected to V + OSNS with a 60.4k 0.5%
TEST1, TEST2, TEST3 (B6, D5, F7):
These pins are for precision resistor. Different output voltages can be pro- µModule initial test purposes. Please connect these pins grammed with an additional resistor between VFB and to GND with a large GND copper area. V – SNS pins. In PolyPhase® operation, tying the VFB pins together allows for parallel operation. See the Applications
MODE/PLLIN (B7):
Mode Selection Pin and External Information section for details. Synchronization Pin. Connect this pin to SGND to force the module into force continuous current mode (CCM) of
SGND (E7):
Signal Ground Pin. Return ground path for all operation. Connect to INTVCC to enable pulse-skipping analog and low power circuitry. Tie a single connection mode of operation. Leaving the pin floating will enable to the output capacitor GND in the application. See layout Burst Mode operation. A clock on the pin will force the guidelines in Figure 22. module into continuous current mode of operation and
SW (F3):
Switching node of the circuit is used for testing synchronized to the external clock applied to this pin. See purposes. Also an R-C snubber network can be applied the Applications Information section. to reduce or eliminate switch node ringing, or otherwise
SVIN (D6):
Signal VIN. Input voltage to the internal 5.5V leave floating. See the Applications Information section. regulator for the control circuitry of the regulator. Tie this
TRACK/SS (F5):
Output Voltage Tracking Pin and Soft-Start pin to VIN pin through a 2.2Ω plus 1µF R-C filter in most Inputs. The pin has a 1.25µA pull-up current. A capacitor application. See the Application Information section. from this pin to ground will set a soft-start ramp rate. In
DRVCC (C5):
Power Input Pin for the MOSFET driver cir- tracking, the regulator output can be tracked to a different cuitry. Connect to INTVCC output for the application with voltage. The voltage ramp rate at his pin sets the voltage the input voltage 6V and above or connect this pin to an ramp rate of the output. See the Applications Information section. 4645f For more information www.linear.com/LTM4645 7 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Package Photo Design Resources Related Parts