MAX1710 Ver la hoja de datos (PDF) - Maxim Integrated
Número de pieza
componentes Descripción
Fabricante
MAX1710 Datasheet PDF : 28 Pages
| |||
High-Speed, Digitally Adjusted
Step-Down Controllers for Notebook CPUs
VBATT 2V TO 28V
RLIM
V+
ILIM
TON
ON-TIME FROM
COMPUTE D/A
TOFF
1-SHOT
Q
TRIG
VCC
5µA
MAX1710
+5V
BST
TON
TRIG
Q
1-SHOT
SQ
R
OVP
SKIP
SHDN
CC
REF
70k
ERROR
AMP
10k
REF
gm
GNDS
FBS
REF
-5%
gm
gm
FB
REF
+12%
REF
-30%
CURRENT
LIMIT
Σ
S
Q
R
DH
LX
ZERO CROSSING
VDD +5V
DL
PGND
FB
CHIP SUPPLY VCC
+5V
PGOOD
S1
S2
Q
OVP/UVLO
LATCH
TIMER
R-2R
D/A CONVERTER
D0 D1 D2 D3
2V REF
REF
GND
OUTPUT
Figure 2. MAX1710 Functional Diagram
IBIAS = ICC + f ✕ (QG1 + QG2) = 15mA to 30mA (typ)
where ICC is 600µA (typ), f is the switching frequency,
and QG1 and QG2 are the MOSFET data sheet total
gate-charge specification limits at VGS = 5V.
Free-Running, Constant-On-Time PWM
Controller with Input Feed-Forward
The Quick-PWM control architecture is an almost fixed-
frequency, constant-on-time current-mode type with volt-
age feed-forward (Figure 2). This architecture relies on
the filter capacitor’s ESR to act as the current-sense
resistor, so the output ripple voltage provides the PWM
ramp signal. The control algorithm is simple: 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. Another one-
shot sets a minimum off-time (400ns typ). The on-time
one-shot is triggered if the error comparator is low, the
______________________________________________________________________________________ 11
Share Link: 