8-Bit Programmable 2- to 4-Phase
Synchronous Buck Controller
ADP3192
FUNCTIONAL BLOCK DIAGRAM
FEATURES
VCC
31
RT RAMPADJ
12 13
Selectable 2-, 3-, or 4-phase operation at up to
1 MHz per phase
±±7± ꢀV worst-case differential sensing error over
teꢀperature
Logic-level PWM outputs for interface to external high
power drivers
Enhanced PWM flex ꢀode for excellent load transient
perforꢀance
SHUNT
REGULATOR
OSCILLATOR
19
30
29
28
OD
UVLO
SHUTDOWN
SET EN
RESET
+
18
1
GND
EN
PWM1
PWM2
PWM3
CMP
–
–
+
850mV
+
RESET
CMP
–
DAC
+ 150mV
+
–
+
RESET
CMP
Active current balancing between all output phases
Built-in power-good/crowbar blanking supports on-the-fly
VID code changes
–
2/3/4-PHASE
CSREF
DRIVER LOGIC
RESET
27 PWM4
+
–
+
CMP
–
DAC
– 350mV
CURRENT
LIMIT
Digitally prograꢀꢀable 075 V to 176 V output supports both
VR107x and VR11 specifications
DELAY
2
PWRGD
CROWBAR
25
24
SW1
SW2
Prograꢀꢀable short-circuit protection with prograꢀꢀable
latch-off delay
10
9
TTSENSE
VRHOT
THERMAL
THROTTLING
CONTROL
23 SW3
VRFAN
8
22
SW4
APPLICATIONS
17
15
CSCOMP
CSREF
11
7
ILIMIT
Desktop PC power supplies for
Next generation Intel® processors
VRM ꢀodules
CURRENT
MEASUREMENT
AND LIMIT
+
–
DELAY
16
21
CSSUM
IMON
20
5
IREF
–
+
4
FB
COMP
GENERAL DESCRIPTION
+
PRECISION
14
LLSET
The ADP31921 is a highly efficient, multiphase, synchronous buck
switching regulator controller optimized for converting a 12 V
main supply into the core supply voltage required by high per-
formance Intel processors. It uses an internal 8-bit DAC to read
a voltage identification (VID) code directly from the processor,
which is used to set the output voltage between 0.5 V and 1.6 V.
REFERENCE
–
BOOT
3
FBRTN
VIDSEL
VOLTAGE
AND
6
SS
SOFT START
CONTROL
VID DAC
40
ADP3192
32
33
34
35
36
37
38
39
VID7 VID6 VID5 VID4 VID3 VID2 VID1 VID0
Figure 1.
This device uses a multimode PWM architecture to drive the
logic-level outputs at a programmable switching frequency that
can be optimized for VR size and efficiency. The phase relation-
ship of the output signals can be programmed to provide 2-, 3-,
or 4-phase operation, allowing for the construction of up to
four complementary buck switching stages.
The ADP3192 has a built-in shunt regulator that allows the part
to be connected to the 12 V system supply through a series resistor.
The ADP3192 is specified over the extended commercial
temperature range of 0°C to 85°C and is available in a
40-lead LFCSP.
The ADP3192 also includes programmable no load offset and
slope functions to adjust the output voltage as a function of the
load current, optimally positioning it for a system transient. The
ADP3192 also provides accurate and reliable short-circuit
protection, adjustable current limiting, and a delayed power-
good output that accommodates on-the-fly output voltage
changes requested by the CPU.
1 Protected by U.S. Patent Number 6,683,441; other patents pending.
Rev7 0
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