MAX1889ETE Maxim Integrated Products, MAX1889ETE Datasheet - Page 10

• Manufacturer Part Number: MAX1889ETE
• Description: DC/DC Switching Converters
• Manufacturer: Maxim Integrated Products

Specifications of MAX1889ETE

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Triple-Output TFT LCD Power Supply
with Fault Protection
10
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PIN
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
NAME
SHDN
PGND
DRVN
TGND
DRVP
FREQ
GATE
GND
OCN
OCP
REF
FBN
FBP
FB
LX
IN
Active-Low Shutdown Control Input. Pull SHDN below the 0.4V logic-low level to turn off all sections
of the device and pull the GATE pin high. Pull SHDN above the 1.6V logic-high level to enable the
device. Do not leave SHDN floating.
Power Ground. PGND is the source of the N-channel power MOSFET. Connect PGND to the analog
ground (GND) at the device’s pins.
Analog Ground. Connect GND to the power ground (PGND) at the device’s pins.
Internal Reference Bypass Terminal. Connect a 0.22µF ceramic capacitor from REF to the analog
ground (GND). External load capability is at least 50µA.
Main Step-Up Regulator Feedback Input. FB regulates to 1.25V nominal. Connect FB to the center of
a resistive voltage-divider between the main output (V
main step-up regulator output voltage. Place the resistive voltage-divider close to the pin.
Negative Linear-Regulator Feedback Input. FBN regulates to 125mV nominal. Connect FBN to the
center of a resistive voltage-divider between the negative output (V
negative linear-regulator output voltage. Place the resistive voltage-divider close to the pin.
Negative Linear-Regulator Base Drive. Open drain of an internal P-channel MOSFET. Connect DRVN
to the base of the external linear-regulator NPN pass transistor (see Pass Transistor Selection
section).
Positive Linear-Regulator Base Drive. Open drain of an internal N-channel MOSFET. Connect DRVP
to the base of the external linear-regulator PNP pass transistor (see Pass Transistor Selection
section).
Positive Linear-Regulator Feedback Input. FBP regulates to 1.25V nominal. Connect FBP to the
center of a resistive voltage-divider between the positive output (V
to set the positive linear-regulator output voltage. Place the resistive voltage-divider close to the pin.
Frequency Select Input. Pull FREQ above logic-high level (0.7 × V
and pull FREQ below logic-low level (0.3 × V
floating.
Switching Node. Drain of the internal N-channel power MOSFET for the main step-up regulator.
Internal connection. Connect this pin to ground.
Overcurrent Comparator Inverting Input. OCN connects to the center tap of a resistive voltage-
divider connected to the drain of the input protection P-channel MOSFET (see the Input Overcurrent
Protection section). If unused, connect OCN to REF.
Overcurrent Comparator Noninverting Input. OCP is connected to the center tap of a resistive
voltage-divider that sets the input overcurrent threshold (see the Input Overcurrent Protection
section). If unused, connect OCP to GND.
Gate Driver Output to the External P-Channel MOSFET (see the Input Overcurrent Protection section).
If unused, leave GATE open.
Supply Input. The supply voltage powers all the control circuitry. The input voltage range is from 2.7V
to 5.5V. Bypass with a 0.1µF ceramic capacitor between IN and GND, as close to the pins as
possible.
IN
FUNCTION
) to set the frequency to 500kHz. Do not leave FREQ
MAIN
) and the analog ground (GND) to set the
IN
POS
NEG
) to set the frequency to 1MHz
) and the analog ground (GND)
) and the REF to set the
Pin Description