MAX8524 MAXIM [Maxim Integrated Products], MAX8524 Datasheet - Page 9

• Manufacturer Part Number: MAX8524
• Description: 2- to 8-Phase VRM 10/9.1 PWM Controllers with Precise Current Sharing and Fast Voltage Positioning
• Manufacturer: MAXIM [Maxim Integrated Products]

(V
MAX8524
IN
INTERLEAVED 8-PHASE OPERATION:
= 12V, V
10
11
12
1
2
3
4
5
6
7
8
9
with Precise Current Sharing and Fast Voltage
LX WAVEFORMS
PIN
OUT
MAX8525
1µs
= 1.2V, I
10
11
12
1
2
3
4
5
6
7
8
9
2- to 8-Phase VRM 10/9.1 PWM Controllers
_______________________________________________________________________________________
OUT_MAX
MAX8524 toc16
PWRGD
CS1_3-
NAME
PWM3
PWM1
COMP
CS1+
CS3+
GND
OSC
V
ILIM
REF
CC
MASTER PH1
MASTER PH2
MASTER PH3
MASTER PH4
SLAVE PH1
SLAVE PH2
SLAVE PH3
SLAVE PH4
= 80A, f
PWM Signal Output for Phase 3. Logic low during shutdown.
PWM Signal Output for Phase 1. Logic low during shutdown
Positive Input of the Output Current Sense of Phase 1. Connect to the inductor side of the
output current-sense resistor.
Common Negative Input of the Output Current Sense of Phases 1 and 3. Connect to the load
side of the output current-sense resistors.
Positive Input of the Output Current Sense of Phase 3. Connect to the inductor side of the
output current-sense resistor.
IC Supply Input. Bypass to GND with a ceramic capacitor of at least 1µF.
IC Ground. Single connection to system ground.
Error-Amplifier Output. Connect to a tap in a resistor-divider from REF to GND to set the finite
DC gain for active voltage positioning. Add a series RC network from COMP to GND to
compensate the control loop. For 6- or 8-phase operation, connect COMP pins of two
controllers together for active current sharing.
2.0V ±0.4% Reference Output. Bypass REF to GND with a ≤2.2µF low-ESR capacitor. REF
can source 0.5mA for external loads. REF is alive when EN is low if V
Output Current-Limit Set. Connect to a tap of a resistor-divider from REF to GND to set the
cycle-by-cycle average current-limit threshold. Current limit (per phase) = V
R
Internal Clock Oscillator Frequency-Set Input. Connect a resistor from OSC to GND to set the
switching frequency. OSC must be connected to an external resistor even if the IC is used in
slave mode. This pin is operational in shutdown if V
Open-Drain Power-Good Indicator. PWRGD pulls low until the output voltage is in regulation.
PWRGD is low in shutdown and during UVLO.
SENSE
SW
= 250kHz, T
). Connect to V
Typical Operating Characteristics (continued)
25
20
15
10
5
0
0.193
8-PHASE ACTIVE CURRENT SHARING
26
A
= +25°C, unless otherwise noted.)
CC
52
LOAD CURRENT (A)
to set the default 20mV current-limit threshold.
77
101
126
FUNCTION
150
CC
is above UVLO.
DYNAMIC VID RESPONSE
8-PHASE OPERATION:
Positioning
Pin Description
40µs
CC
is above UVLO.
ILIM
MAX8524 toc18
/ (50 x
POWER-
GOOD
OUTPUT
PHASE 1
INDUCTOR
CURRENT
10A/div
OUTPUT
VOLTAGE
200mV/div
9