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MAX868EUB+T

P1-P3P4-P6P7-P9P10-P12
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
General Description
The MAX868 inverting charge pump provides a low-cost
and compact means of generating a regulated negative
voltage up to -2 x V
IN
from a positive input voltage
between 1.8V and 5.5V. It uses a pulse-frequency-
modulation (PFM) control scheme to generate the regulat-
ed negative output voltage. PFM operation is obtained
by gating the internal 450kHz oscillator on and off as
needed to maintain output voltage regulation. This
unique on-demand switching scheme gives the MAX868
excellent light-load efficiency without degrading its full-
load operation (up to 30mA), permitting smaller capaci-
tors to take advantage of the oscillator’s high switching
frequency.
The MAX868 requires no inductors; only four capacitors
are required to build a complete DC-DC converter.
Output voltage regulation is achieved by adding just two
resistors. The MAX868 comes in a 10-pin µMAX pack-
age, which is only 1.11mm high and occupies just half
the board area of a standard 8-pin SO.
________________________Applications
Small LCD Panels
Cell Phones
Cordless Phones
Camcorders
Handy-Terminals, PDAs
Medical Instruments
Battery-Operated Equipment
____________________________Features
♦ Regulated Negative Output Voltage
(up to -2 x V
IN
)
♦ Ultra-Small, 10-Pin µMAX Package
♦ On-Demand Switching at up to 450kHz
♦ 30µA Quiescent Supply Current
♦ Requires Only Four Small External Capacitors
♦ 1.8V to 5.5V Input Voltage Range
♦ 0.1µA Logic-Controlled Shutdown
♦ Up to 30mA Output Current
MAX868
Regulated, Adjustable -2x
Inverting Charge Pump
________________________________________________________________
Maxim Integrated Products
1
1
2
3
4
5
10
9
8
7
6
FB
SHDN
C2+
INPGND
C1-
OUT
GND
MAX868
µMAX
TOP VIEW
C2-C1+
Configuration
MAX868
C1+
IN
PGND
SHDN
GND
FB
OUT
0.1µF
1µF
2.2µF
V
OUT
= 0V TO -2 x V
IN
V
IN
= 1.8V TO 5.5V
0.1µF
C1-
C2+
C2-
Typical Operating Circuit
19-1290; Rev 1; 2/98
PART
MAX868C/D
MAX868EUB -40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
Dice*
10 µMAX
Ordering Information
*
Dice are tested at T
A
= +25°C.
MAX868
Regulated, Adjustable -2x
Inverting Charge Pump
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= +3.3V, SHDN = IN, C1 = C2 = 0.22µF, C
IN
= 1µF, C
OUT
= 10µF, T
A
= 0°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
IN to GND.................................................................-0.3V to +6V
OUT to GND...........................................................+0.3V to -12V
IN to OUT.................................................................-0.3V to -17V
C1+ to GND ........................................(V
IN
- 12V) to (V
IN
+ 0.3V)
C1- to GND.............................................................+0.3V to -12V
C2+ to GND....................................................(V
IN
+ 0.3V) to -6V
C2- to GND...............................................................+0.3V to -6V
SHDN, FB to GND .......................................-0.3V to (V
IN
+ 0.3V)
PGND to GND .......................................................-0.3V to +0.3V
Output Current....................................................................35mA
Short-Circuit Duration.................................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
10-pin µMAX (derate 5.6mW/°C above +70°C)...........444mW
Operating Temperature Range
MAX868EUB....................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
FB = IN
No load, V
FB
= -50mV
R
L
= 3kΩ to GND
V
IN
= 5.5V, SHDN = IN or GND
V
IN
= 1.8V to 5.5V
SHDN = GND (OUT pulls to GND)
V
IN
= 1.8V to 5.5V, T
A
= +25°C
I
OUT
= 5mA, FB = IN
No load, SHDN = GND
V
FB
= 50mV
Closed loop
V
OUT
= -5V
CONDITIONS
nA-100 1 100
SHDN Input Bias Current
V
0.7V
IN
V
IH
SHDN Input Threshold
0.3V
IN
V
IL
nA-50 1 50FB Input Bias Current
mA
30
I
OUT
Output Current
12
mA5
I
IN
Supply Current
µA30 50
V1.8 5.5V
IN
Supply-Voltage Range
mV-30 30
15 50
R
OUT
Open-Loop Output
Resistance
Ω
125
70 100
µA0.1 1I
IN
,
SHDN
Shutdown Current
kHz
293 450 607
Oscillator Frequency
270 630
f
OSC
Ω0.2R
OUT,CL
Closed-Loop Output
Resistance
UNITSMIN TYP MAXSYMBOLPARAMETER
T
A
= +25°C
T
A
= 0°C to +85°C
T
A
= +25°C
T
A
= 0°C to +85°C
V
IN
= 3.3V, V
OUT
= -5V
V
IN
= 5V, V
OUT
= -3.3V
V
IN
= 1.8V to 5.5V
mV-40 40
FB Trip Point
T
A
= 0°C to +85°C
T
A
= +25°C
MAX868
Regulated, Adjustable -2x
Inverting Charge Pump
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(V
IN
= +3.3V, C1 = C2 = 0.22µF, C
IN
= 1µF, C
OUT
= 10µF, T
A
= -40°C to +85°C, unless otherwise noted. (Note 1)
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
R
L
= 3kΩ to GND
V
FB
= 50mV
No load, V
FB
= -50mV
No load, SHDN = GND
CONDITIONS
kHz270 630f
OSC
Oscillator Frequency
µA1I
IN,SHDN
Shutdown Current
V1.8 5.5V
IN
Supply-Voltage Range
µA55I
IN
Supply Current
UNITSMIN TYP MAXSYMBOLPARAMETER
I
OUT
= 5mA, FB = IN
V
IN
= 1.8V to 5.5V
SHDN = GND (OUT pulls to GND)
V
IN
= 1.8V to 5.5V
nA-100 100FB Input Bias Current
mV-40 40FB Trip Point
125
Open-Loop Output
Resistance
Ω
50
R
OUT
V
IN
= 5.5V, SHDN = IN or GND
V
IN
= 1.8V to 5.5V
nA-100 100
SHDN Input Bias Current
V
0.7V
IN
V
IH
SHDN Input Threshold
0.3V
IN
V
IL
__________________________________________Typical Operating Characteristics
(Circuit of Figure 5, T
A
= +25°C, unless otherwise noted.)
-35
-25
-30
-20
-5
0
-10
-15
5
0 10 15 20 255 30 35 40 45 50
LOAD-REGULATION ERROR
vs. LOAD CURRENT
(V
IN
= 5V)
MAX868-01
LOAD CURRENT (mA)
LOAD-REGULATION ERROR (mV)
V
OUT
= -7.5V
V
OUT
= -3.3V
V
OUT
= -5V
-15
-9
-12
0
-3
-6
3
0 5 10 15 20 25
LOAD-REGULATION ERROR
vs. LOAD CURRENT
(V
IN
= 3.3V)
MAX868-02
LOAD CURRENT (mA)
LOAD-REGULATION ERROR (mV)
V
OUT
= -3.3V
V
OUT
= -5V
400
410
430
440
420
480
470
460
450
500
490
-40 -20 0 20 40 60 80 100
MAXIMUM SWITCHING FREQUENCY
vs. TEMPERATURE
MAX868-03
TEMPERATURE (°C)
MAXIMUM SWITCHING FREQUENCY (kHz)
FB = IN
V
IN
= 3.3V
V
IN
= 2V
V
IN
= 5V
P1-P3P4-P6P7-P9P10-P12

MAX868EUB+T

Mfr. #:
Buy MAX868EUB+T
Manufacturer:
Maxim Integrated
Description:
Switching Voltage Regulators Reg/Adj -2x Invertin Charge Pump
Lifecycle:
New from this manufacturer.
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