MAX686EEE Maxim Integrated Products, MAX686EEE Datasheet - Page 7

• Manufacturer Part Number: MAX686EEE
• Description: INVERT BOOST DAC-CONTROL 16QSOP
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost), Invertingr

Specifications of MAX686EEE

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: ±27.5V
• Current - Output: 100mA
• Frequency - Switching: 300kHz
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Power - Output: 667mW
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q1752000

(Circuits of Figures 1 and 2, V
_____________________________Typical Operating Characteristics (continued)
PIN
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
5V/div
5V/div
SHDN
V
OUT
DACOUT
LCDON
NAME
PGND
SHDN
GND
ISET
POK
N.C.
POL
V
REF
V
DN
UP
FB
LX
DD
CC
I
R
SET
L
= 4.7k
(NEGATIVE CONFIGURATION)
= V
_______________________________________________________________________________________
CC
POWER-UP RESPONSE
Power Ground. Connect to GND.
Increment Output Voltage Input. Increments the DAC on each rising edge such that
Decrement Output Voltage Input. Decrements the DAC on each rising edge such that
Polarity Input. Changes polarity and threshold of FB to allow regulation of either positive or negative output
voltages. POL also changes the polarity of the DAC output such that increasing codes always increases the
magnitude of the output voltage. Set POL = GND for positive output voltage, or set POL = V
output voltage.
Gate-Drive Supply for Internal MOSFET. Connect to V
Set LX Current Limit. Sets the peak current limit for the internal switch. Connect to V
limit. Connect to GND for 250mA current limit.
Shutdown Input. A logic low on SHDN places the MAX686 in shutdown mode. Connect to V
operation.
DAC Output Voltage
Reference Output. Bypass with a 0.1µF ceramic capacitor to GND.
Feedback Input. Connect to an external voltage divider to set the MAX686 output voltage. See the section
Setting the Output Voltage with the DAC .
Power-OK Sense Input/Power-OK Comparator Input. When the voltage applied to POK is greater than
1.125V, LCDON is low. Connect to a resistive voltage divider monitoring V
IC Power-Supply Input
Ground
Power-OK Comparator Open-Drain Output. Connect to external switch to turn LCD power on or off. See the
section Controlling the LCD Using POK and
No Connection. Not internally connected.
Drain of Internal 28V, 500mA N-Channel Switch
LCD Bias Supply with Internal Switch
500 s
CC
= V
DD
= V
MAX686 TOC14A
IN
= +5V, L1 = 22µH, SHDN = V
DAC-Controlled Boost/Inverter
0V
-16.8V
LCDON .
FUNCTION
CC
5V/div
5V/div
SHDN
V
CC
, C
OUT
.
REF
= 0.1µF, T A = +25°C, unless otherwise noted.)
(NEGATIVE CONFIGURATION)
POWER-DOWN RESPONSE
IN
20ms/div
or V
OUT
Pin Description
.
I
R
CC
SET
L
MAX686 TOC14B
|
V
= 4.7k
= V
OUT
|
for 500mA current
V
CC
OUT
|
CC
increases.
CC
|
decreases.
0V
-16.8V
for normal
for negative
7