MAX8770GTL+T Maxim Integrated Products, MAX8770GTL+T Datasheet - Page 20

• Manufacturer Part Number: MAX8770GTL+T
• Description: IC CTLR PS 2/1PH QUICK PWM 40QFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8770GTL+T

• Applications: Controller, Intel IMVP-6
• Voltage - Input: 4 ~ 26 V
• Number Of Outputs: 1
• Voltage - Output: 0.125 ~ 1.5 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: *
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PWM Controller for IMVP-6+ CPU Core Power Supplies
CONFIDENTIAL INFORMATION – RESTRICTED TO INTEL
The Quick-PWM control architecture is a pseudo-fixed-
frequency, constant-on-time, current-mode regulator
with voltage feed-forward (Figure 2). This architecture
relies on the output filter capacitor’s ESR to act as the
current-sense resistor, so the output ripple voltage pro-
Figure 2. Functional Block Diagram
20
______________________________________________________________________________________
Free-Running, Constant On-Time PWM
MAX8770/MAX8771/MAX8772
MAX8770/MAX8771/MAX8772 Dual-Phase, Quick-
Controller with Input Feed-Forward
THRM
VRHOT
CSP2
CSN2
CSP1
CSN1
VCC
REF
GND
TIME
D0–D6
SHDN
CCV
FB
GNDS
Detailed Description
G
(2.0V)
G
m
REF
m
(FB)
(CCV)
FAULT
REF
x2
DAC
CSP_
CSN_
22.5mV
22.5mV
CONVERTER
0.3 x V
R-TO-I
CC
MAX8770
MAX8771
MAX8772
DPRSLPVR
DPRSTP
PHASE CONTROL
Q
T
Q
Q
ONE-SHOT
MINIMUM
OFF-TIME
BLANK
- 300mV
TARGET
2.5mV
CSP1
CSN1
TRIG
vides the PWM ramp signal. The control algorithm is sim-
ple: the high-side switch on-time is determined solely by
a one-shot whose period is inversely proportional to
input voltage, and directly proportional to output voltage
or the difference between the main and secondary
inductor currents (see the On-Time One-Shot section).
Another one-shot sets a minimum off-time. The on-time
one-shot triggers when the error comparator goes low,
the inductor current of the selected phase is below the
valley current-limit threshold, and the minimum off-time
one-shot times out. The controller maintains 180° out-of-
Q
Q
PHASE DRIVERS
ONE-SHOT
ONE-SHOT
SECONDARY
PHASE 2
ON-TIME
PHASE 1
ON-TIME
TRIG
TRIG
R
S
+ 200mV
TARGET
CSN1 - GNDS
CSP1 - CSN1
CSP2 - CSN2
Q
S
R
MAIN PHASE
CURRENT-
BALANCE-
FB
Q
DRIVERS
FAULT
STARTUP
DELAY
MONITOR
60µs
POWER
®
STARTUP
DELAY
G
G
5ms
m
m
BLANK
IMVP-6 LICENSEES
(CCI)
(CCI)
STARTUP
DELAY
5ms
CSN2
CSP2
CSP1
CSN1
PWRGD
PHASEGD
CLKEN
PGND1
PGND2
POUT
BST2
BST1
DH2
DL2
TON
DH1
V
DL1
LX2
CCI
LX1
DD