LTM4628 PIN FUNCTIONS (Recommended to Use Test Points to Monitor Signal Pin Connections.) TRACK1, TRACK2 (E5, D8): Output Voltage Tracking Pin DIFFOUT (F8): Internal Remote Sense Amplifier Output. and Soft-Start Inputs. Each channel has a 1.3µA pull-up Connect this pin to VOUTS1 or VOUTS2 depending on which current source. When one channel is configured to be output is using remote sense. In parallel operation con- master of the two channels, then a capacitor from this pin nect one of the VOUTS pin to DIFFOUT for remote sensing. to ground will set a soft-start ramp rate. The remaining Leave floating if the remote sense amplifier is not used. channel can be set up as the slave, and have the master’s SW1, SW2 (G2, G11): Switching node of each channel output applied through a voltage divider to the slave out- that is used for testing purposes. Also an R-C snubber put’s track pin. This voltage divider is equal to the slave network can be applied to reduce or eliminate switch node output’s feedback divider for coincidental tracking. See ringing, otherwise leave floating. See the Applications the Applications Information section. Information section. COMP1, COMP2 (E6, E7): Current control threshold and PHASMD (G4): Connect this pin to SGND, INTV error amplifier compensation point for each channel. The CC, or float- ing this pin to select the phase of CLKOUT to 60 degrees, current comparator threshold increases with this control 120 degrees, and 90 degrees respectively. voltage. Tie the COMP pins together for parallel operation. The device is internal compensated. CLKOUT (G5): Clock output with phase control using the PHASMD pin to enable multiphase operation between DIFFP (E8): Positive input of the remote sense amplifier. devices. See the Applications Information section. This pin is connected to the remote sense point of the output voltage. Use of the remote sense amplifier is limited to an PGOOD1, PGOOD2 (G9, G8): Output Voltage Power output voltage between 0.6V and 3.3V inclusive. Connect to Good Indicator. Open drain logic output that is pulled to GND if not used. See the Applications Information section. ground when the output voltage is not within ±7.5% of the regulation point. DIFFN (E9): Negative input of the remote sense amplifier. This pin is connected to the remote sense point of the INTVCC (H8): Internal 5V Regulator Output. The control output GND. See the Applications Information section. circuits and internal gate drivers are powered from this voltage. INTV MODE_PLLIN (F4): Force Continuous Mode, Burst Mode CC is controlled and enabled when RUN1 or RUN2 is activated high. Decouple this pin to PGND with Operation, or Pulse-Skipping Mode Selection Pin and a 4.7µF low ESR tantalum or ceramic. External Synchronization Input to Phase Detector Pin. Connect this pin to SGND to force both channels into TEMP (J6): Onboard Temperature Diode for Monitoring force continuous mode of operation. Connect to INTVCC the VBE Junction Voltage Change with Temperature. See to enable pulse-skipping mode of operation. Leaving the the Applications Information section. pin floating will enable Burst Mode operation. A clock on EXTV the pin will force both channels into continuous mode of CC (J7): External power input that is enabled through a switch to INTV operation and synchronized to the external clock applied CC whenever EXTVCC is greater than 4.7V. Do not exceed 6V on this input, and connect this pin to to this pin. VIN when operating VIN on 5V. An efficiency increase will RUN1, RUN2 (F5, F9): Run Control Pin. A voltage above occur that is a function of the (VIN – INTVCC) multiplied by 1.25V will turn on each channel in the module. A voltage power MOSFET driver current. Typical current requirement below 1.25V on the RUN pin will turn off the related chan- is 30mA. VIN must be applied before EXTVCC, and EXTVCC nel. Each RUN pin has a 1µA pull-up current, once the must be removed before VIN. RUN pin reaches 1.2V an additional 4.5µA pull-up current V is added to this pin. IN (M2-M11, L2-L11, J2-J4, J9-J11, K2-K4, K9-K11): Power Input Pins. Apply input voltage between these pins and GND pins. Recommend placing input decoupling capacitance directly between VIN pins and GND pins. 4628fe 8 For more information www.linear.com/LTM4628 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Package Photos Revision History Typical Application Related Parts