Datasheet LTM4650 (Analog Devices) - 8

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PIN FUNCTIONS (Recommended to Use Test Points to Monitor Signal Pin Connections.) PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY. VOUT1 (A1-A5, B1-B5, C1-C4):
Power Output Pins.
VFB1, VFB2 (D5, D7):
The Negative Input of the Error Apply output load between these pins and GND pins. Amplifier for Each Channel. Internally, this pin is con- Recommend placing output decoupling capacitance nected to VOUTS1 or VOUTS2 with a 60.4kΩ precision directly between these pins and GND pins. Review Table 4. resistor. Different output voltages can be programmed
GND (A6-A7, B6-B7, D1-D4, D9-D12, E1-E4, E10-E12,
with an additional resistor between VFB and GND pins. In
F1-F3, F10-F12, G1, G3, G10, G12, H1-H7, H9-H12, J1,
PolyPhase® operation, tying the VFB pins together allows
J5, J8, J12, K1, K5-K8, K12, L1, L12, M1 , M12):
Power for parallel operation. See the Applications Information Ground Pins for Both Input and Output Returns. section for details.
V TRACK1, TRACK2 (E5, D8):
Output Voltage Tracking Pin
OUT2 (A8-A12, B8-B12, C9-C12):
Power Output Pins. Apply output load between these pins and GND pins. and Soft-Start Inputs. Each channel has a 1.3µA pull-up Recommend placing output decoupling capacitance current source. When one channel is configured to be directly between these pins and GND pins. Review Table 4. master of the two channels, then a capacitor from this pin to ground will set a soft-start ramp rate. The remaining
VOUTS1, VOUTS2 (C5, C8):
This pin is connected to the top channel can be set up as the slave, and have the master’s of the internal top feedback resistor for each output. The output applied through a voltage divider to the slave out- pin can be directly connected to its specific output, or put’s track pin. This voltage divider is equal to the slave connected to DIFFOUT when the remote sense amplifier is output’s feedback divider for coincidental tracking. See used. In paralleling modules, one of the VOUTS pins is con- the Applications Information section. nected to the DIFFOUT pin in remote sensing or directly to V
COMP1, COMP2 (E6, E7):
Current control threshold and OUT with no remote sensing. It is very important to connect these pins to either the DIFFOUT or V error amplifier compensation point for each channel. The OUT since this is the feedback path, and cannot be left open. See the current comparator threshold increases with this control Applications Information section. voltage. Tie the COMP pins together for parallel operation. The device is internal compensated.
fSET (C6):
Frequency Set Pin. A 10µA current is sourced from this pin. A resistor from this pin to ground sets a
DIFFP (E8):
Positive input of the remote sense amplifier. voltage that in turn programs the operating frequency. This pin is connected to the remote sense point of the Alternatively, this pin can be driven with a DC voltage output voltage. See the Applications Information section. that can set the operating frequency. See the Applications
DIFFN (E9):
Negative input of the remote sense amplifier. Information section. This pin is connected to the remote sense point of the
SGND (C7, D6, G6-G7, F6-F7):
Signal Ground Pin. Return output GND. See the Applications Information section. ground path for all analog and low power circuitry. Tie
MODE_PLLIN (F4):
Force Continuous Mode, Burst Mode a single connection to the output capacitor GND in the Operation, or Pulse-Skipping Mode Selection Pin and application. See layout guidelines in Figure 11. External Synchronization Input to Phase Detector Pin. Connect this pin to SGND to force both channels into force continuous mode of operation. Connect to INTVCC to enable pulse-skipping mode of operation. Leaving the pin floating will enable Burst Mode operation. A clock on the pin will force both channels into continuous mode of operation and synchronized to the external clock applied to this pin. Rev. C 8 For more information www.analog.com Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Operation Applications Information Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Revision History Package Photo Design Resources Related Parts