MAX1715 Maxim, MAX1715 Datasheet - Page 8

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

Ultra-High Efficiency, Dual Step-Down
Controller for Notebook Computers
8
15, 23,
PIN
10
11
12
13
14
28
_______________________________________________________________________________________
1
2
3
4
5
6
7
8
9
PGOOD
NAME
AGND
OUT1
ILIM1
ILIM2
OUT2
SKIP
TON
ON1
ON2
N.C.
FB1
REF
FB2
V+
Output Voltage Connection for the OUT1 PWM. Connect directly to the junction of the external inductor and
output filter capacitors. OUT1 senses the output voltage to determine the on-time and also serves as the
feedback input in fixed-output modes.
Feedback Input for OUT1. Connect to AGND for 1.8V fixed output or to V
to a resistor-divider from OUT1 for an adjustable output.
Current-Limit Threshold Adjustment for OUT1. The LX1-PGND current-limit threshold defaults to +100mV if
ILIM1 is connected to V
current through R
limit voltage. Choose R
Battery Voltage Sense Connection. Connect to the input power source. V+ is used only to set the PWM one-
shot timing.
On-Time Selection Control Input. This is a four-level input used to determine DH_ on-time. The TON table
below is for V
TON
AGND
REF
Open
V
Pulse-Skipping Control Input. Connect to V
pulse-skipping operation.
Power-Good Open-Drain Output. PGOOD is low when either FB_ input is more than 5.5% below the normal
regulation point (typ).
Analog Ground
+2.0V Reference Voltage Connection. Bypass to AGND with 0.22µF (min) capacitor. Can supply 50µA for
external loads.
OUT1 ON/OFF Control Input. Drive to AGND to turn OUT1 off. Drive to V
OUT2 ON/OFF Control Input. Drive to AGND to turn OUT2 off. Drive to V
Current-Limit Threshold Adjustment for OUT2. The LX2-PGND current-limit threshold defaults to +100mV if
ILIM2 is connected to V
current through R
limit voltage. Choose R
Feedback Input for OUT2. Connect to AGND for 2.5V fixed output, or connect to a resistor-divider from
OUT2 for an adjustable output.
Output Voltage Connection for the OUT2 PWM. Connect directly to the junction of the external inductor and
output filter capacitors. OUT2 senses the output voltage to determine the on-time and also serves as the
feedback input in fixed-output mode.
No Connection. These pins are not connected to any internal circuitry. Connect the N.C. pins to the ground
plane to enhance thermal conductivity.
CC
IN
= 24V, V
EXT
EXT
sets the threshold from 50mV to 200mV. The voltage on the pin is 10 times the current-
sets the threshold from 50mV to 200mV. The voltage on the pin is 10 times the current-
EXT
EXT
CC
CC
OUT1
. Or, connect an external resistor to AGND to adjust the limit. A precision 5µA pull-up
. Or, connect an external resistor to AGND to adjust the limit. A precision 5µA pull-up
equal to 2kΩ per mV of current-limit threshold (100kΩ to 400kΩ).
equal to 2kΩ per mV of current-limit threshold (100kΩ to 400kΩ).
Frequency (OUT1) (kHz)
620
485
345
235
= 1.8V, V
OUT2
CC
= 2.5V condition.
for low-noise forced-PWM mode. Connect to AGND to enable
FUNCTION
170
Frequency (OUT2) (kHz)
460
355
255
170
CC
CC
CC
to turn OUT1 on.
to turn OUT2 on.
for 3.3V fixed output, or connect
Pin Description