6-Bit, Programmable 2-/3-/4-Phase,
Synchronous Buck Controller
Selectable 2-, 3-, or 4-phase operation
Up to 1 MHz per phase
±9.5 mV worst-case differential sensing error
Logic-level PWM outputs for interface to external
high power drivers
PWM Flex-ModeTM architecture for excellent load
Active current balancing between all output phases
Built-in power good/crowbar blanking supports OTF VID
6-bit digitally programmable 0.8375 V to 1.6 V output
Programmable short circuit protection with programmable
Desktop PC power supplies for
Next-generation Intel® processors
FUNCTIONAL BLOCK DIAGRAM
DAC + 150mV
DAC – 250mV
The ADP31941 is a highly efficient, multiphase, synchronous
buck switching regulator controller optimized for converting a
5 V or 12 V main supply into the core supply voltage required
by high performance Intel processors. It uses an internal 6-bit
DAC to read a voltage identification (VID) code directly from
the processor that is used to set the output voltage between
0.8375 V and 1.6 V. The device uses a multimode PWM archi-
tecture to drive the logic-level outputs at a programmable
switching frequency that can be optimized for VR size and
efficiency. The phase relationship 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 switch-
VID4 VID3 VID2 VID1 VID0 VID5
Figure 1. Functional Block Diagram
The ADP3194 also includes programmable, no-load offset,
and slope functions to adjust the output voltage as a function
of the load current, so it is always optimally positioned for a
system transient. The ADP3194 also provides accurate and
reliable short-circuit protection, adjustable current limiting,
and a delayed power good output that accommodates on-the-
fly (OTF) output voltage changes requested by the CPU.
The devices are specified over the commercial temperature
range of 0°C to +85°C and are available in a 28-lead TSSOP.
1 Protected by U. S. Patent Number 6,683,441; other patents pending.
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