LTC3734 Datasheet, PDF (1/28 Pages) Linear Technology – Single-Phase, High Efficiency DC/DC Controller for Intel Mobile CPUs

LTC3734
Single-Phase,
High Efficiency DC/DC
Controller for Intel Mobile CPUs
FEATURES
■ _{Wide Input Voltage Range: 4V to 30V}
■ _{±1% Output Voltage Accuracy}
■ _{6-Bit IMVP-IV VID Code: VOUT = 0.7V to 1.708V}
■ _{Intel Compatible Power Saving Mode (PSIB)}
■ _{Power Good Output with Adaptive Masking}
■ _{Lossless Voltage Positioning}
■ _{Resistor Programmable VOUT at Boot-Up and}
Deeper Sleep State
■ _{Resistor Programmable Deep Sleep Offset}
■ _{Programmable Fixed Frequency: 210kHz to 550kHz}
■ _{Adjustable Soft-Start Current Ramping}
■ _{Foldback Output Current Limit}
■ _{Short-Circuit Shutdown Timer with Defeat Option}
■ _{Overvoltage Protection}
■ _{Available in 32-Lead 5mm × 5mm × 0.8mm (Profile)}
QFN Package
U
APPLICATIO S
■ _{Mobile and Desktop Computers}
■ _{Internet Servers}
DESCRIPTIO
The LTC^®3734 is a single-phase synchronous step-down
switching regulator controller that drives all N-channel
power MOSFETs in a constant frequency architecture. The
output voltage is programmable by six VID bits during
normal operation and by external resistors during initial
boot-up and deeper sleep state. The LTC3734 drives its
output stage at frequencies up to 550kHz. Powerful on-
chip gate drivers eliminate the need for external gate driver
ICs, thus simplifying the design.
An Intel compatible PSIB input is provided to select between
two modes of operation. Fully enhanced synchronous mode
achieves a very small output ripple and very fast transient
response while power saving mode realizes very high ef-
ficiency. OPTI-LOOP^® compensation allows the transient
response to be optimized for a wide range of output capaci-
tance and ESR values.
The LTC3734 is available in a small 5mm × 5mm QFN
package. For 2-phase applications refer to the LTC3735.
, LTC and LT are registered trademarks of Linear Technology Corporation.
OPTI-LOOP is a registered trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
100pF
4.5V TO 7V
6-BIT VID
R_C
3k
C_C
680pF
0.1μF
4.7μF BAT54A
0.47μF
MCH_PG
TG
DPRSLPVR
SW
STP_CPUB
BG
PSIB
PGND
FREQSET
SENSE⁺
VID5-VID0 _SENSE–
PGOOD
LTC3734
I_TH
RBOOT
RUN/SS ^RDPRSLP
RDPSLP
SGND
PV_CC
V_OA+
OAOUT
V_OA–
BOOST
SV_CC
M1
0.8μH
M2 D1
12.7k
56.2k
1.27M
13.3k
13.3k 1.27M
4.5V TO 7V
0.1μF
0.002Ω
SW
3734 F01
Figure 1. High Current Step-Down Converter
C_IN
10μF
35V
×4
V_IN
5V TO 24V
V_OUT
0.7V TO 1.708V
+ ^{COUT 20A}
270μF
2V
×3
3734f
1