MAX1981A Maxim Integrated Products, MAX1981A Datasheet - Page 26

• Manufacturer Part Number: MAX1981A
• Description: (MAX1907A / MAX1981A) Quick-PWM Master Controllers
• Manufacturer: Maxim Integrated Products

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Quick-PWM Master Controllers for Voltage-
Positioned CPU Core Power Supplies (IMVP-IV)
26
Table 4. Operating Mode Truth Table
SHDN
0
1
1
1
1
1
______________________________________________________________________________________
SYSPOK
x
0
1
1
x
0
SUS
0
0
0
1
x
x
DPSLP
x
x
1
0
x
x
DDO
0
1
1
0
0
0
(Plus offset)
VOLTAGE
(No offset)
(No offset)
(No offset)
OUTPUT
D0–D5
D0–D5
B0–B2
S0–S2
GND
GND
Low-Power Shutdown Mode. DL is forced high (V
DH is forced low (LX), and the PWM controller is
disabled. The supply current drops to 0.1µA (typ).
Power-Up Mode. When enabled, the MAX1907A/
MAX1981A softly ramps up the output voltage to the
selected boot voltage (B0–B2, Table 7). The controller
remains at the boot voltage until SYSPOK is driven high
(see the Power-Up Sequence section).
Normal Operation. The no-load output voltage is
determined by the selected VID DAC code (D0–D5,
Table 5).
Deep-Sleep Mode. The no-load output voltage is
determined by the selected VID DAC code (D0–D5,
Table 5) plus the offset voltage set by POS and NEG.
Operation with automatic PWM/PFM switchover for
pulse skipping under light loads.
Suspend Mode. The no-load output voltage is
determined by the selected suspend code (S0–S2,
Table 6). Operation with automatic PWM/PFM
switchover for pulse skipping under light loads.
Fault Mode. The fault latch has been set by either UVP,
OVP (MAX1907A only), thermal shutdown, or a falling
edge on SYSPOK. The controller will remain in FAULT
mode until V
CC
power is cycled or SHDN toggled.
OPERATING MODE
DD
),