LTC3735EUHF Linear Technology, LTC3735EUHF Datasheet - Page 27

• Manufacturer Part Number: LTC3735EUHF
• Description: IC CTRLR DC/DC 2PH HI EFF 38-QFN
• Manufacturer: Linear Technology

Specifications of LTC3735EUHF

• Applications: Controller, Intel Mobile CPU
• Number Of Outputs: 1
• Voltage - Output: 0.7 ~ 1.71 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 38-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Voltage - Input: -

Simplified Visual Explanation of How a 2-Phase
Controller Reduces Both Input and Output RMS Ripple
Current
A multiphase power supply significantly reduces the
amount of ripple current in both the input and output
capacitors. The RMS input ripple current is divided by, and
the effective ripple frequency is multiplied up by the
number of phases used (assuming that the input voltage
is greater than the number of phases used times the output
voltage). The output ripple amplitude is also reduced by,
and the effective ripple frequency is increased by the
number of phases used. Figure 13 graphically illustrates
the principle.
APPLICATIO S I FOR ATIO
R
IN
V
IN
C
IN
BOLD LINES INDICATE
HIGH, SWITCHING
CURRENT LINES.
KEEP LINES TO A
MINIMUM LENGTH.
+
U
Figure 12. Instantaneous Current Path Flow in a Multiple Phase Switching Regulator
U
W
SW1
SW2
D1
D2
U
SW V
I
L1
L2
COUT
I
CIN
Figure 13. Single and 2-Phase Current Waveforms
R
R
SENSE1
SENSE2
SINGLE PHASE
3735 F12
+
SW1 V
SW2 V
C
I
V
COUT
OUT
OUT
I
CIN
I
I
L1
L2
DUAL PHASE
LTC3735
27
R
L
RIPPLE
3735 F13
3735f