Datasheet LTM4650A-1 (Analog Devices) - 8

LTM4650A-1
PIN FUNCTIONS (Recommended to Use Test Points to Monitor Signal Pin Connections.) PACKAGE ROW AND COLUMN LABELING MAY VARY
Different output voltages can be programmed with an ad-
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
ditional resistor between VFB and GND pins. In PolyPhase®
LAYOUT CAREFULLY.
operation, tying the V
V
FB pins together allows for parallel
OUT1 (A1–A5, B1–B5, C1–C4):
Power Output Pins. Apply operation. See the Applications Information section for output load between these pins and GND pins. Recommend details. Do not drive this pin. placing output decoupling capacitance directly between these pins and GND pins. Review Table 6.
TRACK1, TRACK2 (E5, D8):
Output Voltage Tracking Pin and Soft-Start Inputs. Each channel has a 1.3µA pull-up
GND (A6–A7, B6–B7, D1–D4, D9–D12, E1–E4, E10–E12,
current source. When one channel is configured to be
F1–F3, F10–F12, G1, G3, G10, G12, H1–H7, H9–H12,
master of the two channels, then a capacitor from this pin
J1, J5, J8, J12, K1, K5–K8, K12, L1, L12, M1 , M12):
to ground will set a soft-start ramp rate. The remaining Power Ground Pins for Both Input and Output Returns. channel can be set up as the slave, and have the master’s
VOUT2 (A8–A12, B8–B12, C9–C12):
Power Output Pins. output applied through a voltage divider to the slave out- Apply output load between these pins and GND pins. Rec- put’s track pin. This voltage divider is equal to the slave ommend placing output decoupling capacitance directly output’s feedback divider for coincidental tracking. See between these pins and GND pins. Review Table 6. the Applications Information section.
VOUTS1, VOUTS2 (C5, C8):
This pin is connected to the top
COMP1, COMP2 (E6, E7):
Current control threshold and of the internal top feedback resistor for each output. The error amplifier compensation point for each channel. The pin can be directly connected to its specific output, or current comparator threshold increases with this control connected to DIFFOUT when the remote sense amplifier voltage. COMP pin internal has 10pF filter cap to SGND. is used. In paralleling modules, one of the VOUTS pins is An external RC filter circuit is required for control loop connected to the DIFFOUT pin in remote sensing or directly compensation. See Applications Information section. Tie to VOUT with no remote sensing. It is very important to the COMP pins together for parallel operation. Do not connect these pins to either the DIFFOUT or VOUT since drive this pin. this is the feedback path, and cannot be left open. See the
DIFFP (E8):
Positive input of the remote sense amplifier. Applications Information section. This pin is connected to the remote sense point of the
fSET (C6):
Frequency Set Pin. A 10µA current is sourced output voltage. Diffamp can be used for ≤3.3V outputs. from this pin. A resistor from this pin to ground sets a See the Applications Information section. voltage that in turn programs the operating frequency.
DIFFN (E9):
Negative input of the remote sense amplifier. Alternatively, this pin can be driven with a DC voltage This pin is connected to the remote sense point of the that can set the operating frequency. See the Applications output GND. Diffamp can be used for ≤3.3V outputs. See Information section. the Applications Information section.
SGND (C7, D6, G6–G7, F6–F7):
Signal Ground Pin. Return
MODE_PLLIN (F4):
Force Continuous Mode, Burst Mode ground path for all analog and low power circuitry. Tie a Operation, or Pulse-Skipping Mode Selection Pin and single connection to the output capacitor GND in the ap- External Synchronization Input to Phase Detector Pin. plication. See layout guidelines in Figure 14. Connect this pin to SGND to force both channels into
VFB1, VFB2 (D5, D7):
The Negative Input of the Error Am- force continuous mode of operation. Connect to INTVCC plifier for Each Channel. Internally, this pin is connected to enable pulse-skipping mode of operation. Leaving the to VOUTS1 or VOUTS2 with a 60.4kΩ precision resistor. 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. 4650a1f 8 For more information www.linear.com/LTM4650A-1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Typical Application Package Photo Design Resources Related Parts