MAX1715 Maxim, MAX1715 Datasheet - Page 13

• Manufacturer Part Number: MAX1715
• Description: Ultra-High Efficiency / Dual Step-Down Controller for Notebook Computers
• Manufacturer: Maxim

Table 3. Operating Mode Truth Table
Figure 3. PWM Controller (one side only)
X = Don’t care
ON1
0
0
1
X
1
1
ON2
X
0
1
0
1
1
TO PGOOD
OR GATE
<-0.3V
AGND
SKIP
V
______________________________________________________________________________________
X
X
X
DD
2V TO 28V
IN
Ultra-High Efficiency, Dual Step-Down
TON
OUT1 Disable Disable OUT1. DL1 = V
OUT2 Disable Disable OUT2. DL2 = V
SHUTDOWN Low-power shutdown state. DL = V
RUN (PWM)
(PFM/PWM)
Low Noise
No Fault
FROM ILIM
COMPARATOR
-6%
MODE
REF
RUN
TRIG
Controller for Notebook Computers
FROM ZERO-CROSSING COMPARATOR
COMPUTE
ON-TIME
1-SHOT
TON
TON
V+
OVP/UVLO
Disables the output overvoltage and undervoltage fault circuitry.
Low-Noise operation with no automatic PWM/PFM switchover. Fixed-frequency PWM
action is forced regardless of load. Inductor current reverses at light load levels. I
draw <1.5mA (typ) plus gate-drive current.
Normal operation with automatic PWM/PFM switchover for pulse-skipping at light loads.
I
DD
LATCH
Q
+12%
FROM
REF
REF
<1.5mA (typ) plus gate drive current.
OUT
S1
Q
S2
-30%
REF
TIMER
ERROR
AMP
Q
DD
DD
1-SHOT
S
R
TOFF
. Clears OUT1 fault latches.
. Clears OUT2 fault latches.
Q
TRIG
DD
S
R
(SEE FIGURE 9)
COMMENTS
. Clears fault latches.
FEEDBACK
Q
MUX
x2
OUT_
FB_
TO DH DRIVER
TO DL DRIVER
DD
13