Low-Noise, Regulated, Negative
Charge-Pump Power Supplies for GaAsFET Bias
MAX850–MAX853
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
IN
to GND ..................................-0.3V to 10.5V
V
NEGOUT
to GND ...................................................-10.5V to 0.3V
V
IN to
V
NEGOUT
.........................................................-0.3V to 21V
V
OUT
to GND (Note 1) ........................................V
NEGOUT
to 0.3V
SHDN or OSC (pin 4) Voltage to GND.........-0.3V to (V
IN
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) ........................471mW
Operating Temperature Ranges
MAX85_ISA ......................................................-25°C to +85°C
MAX85_ESA.....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1:
The output may be shorted to NEGOUT or GND if the package power dissipation is not exceeded. Typical short-circuit
current to GND is 50mA.
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.
ELECTRICAL CHARACTERISTICS
(+5V
≤
V
IN
≤
+10V, GND = 0V, V
OUT
= -4.1V, R
L
=
∞,
T
A
= T
MIN
to T
MAX
, unless otherwise noted. A 100kHz, 50% duty cycle square
wave between GND and V
IN
is applied to OSC on the MAX852.)
PARAMETER
Supply Voltage Range (Note 2)
SYMBOL
V
IN
MAX850–MAX852, V
FB
= 0V,
R
L
=
∞
or 820Ω, Figure 2a
MAX853, V
CTRL
= 4.1V,
R
L
=
∞
or 820Ω, Figure 2c
CONDITIONS
MIN
5
-4.3
-4.2
-0.5 to -(V
IN
- 1)
V
FBset
I
Q
MAX850/MAX853, V
IN
= 10V, SHDN = 0V
Shutdown Supply Current
I
SHUT
MAX851, SHDN = 2V
MAX852, OSC low
MAX850–MAX852, V
FB
= 0V,
R
L
=
∞
or 820Ω, Figure 2a
V
OUT
Load Regulation
MAX853, V
CTRL
= 4.1V,
R
L
=
∞
or 820Ω, Figure 2c
V
OUT
Ripple
Oscillator Frequency (Note 3)
Input High Voltage
Input Low Voltage
Input Current
Input Capacitance
f
OSC
V
IH
V
IL
I
IN
C
IN
MAX850–MAX852
MAX853
MAX850/MAX851/MAX853, T
A
= +25°C
Pin 4
Pin 4
Pin 4
Pin 4
10
80
2.0
0.5
±1
3
2
1
100
120
8
4
MAX850–MAX852, no load, Figure 2b
-1.32
-1.28
2.0
0.002
2
-1.24
3.0
1
5
1
8
mV/mA
µA
-4.1
TYP
MAX
10
-3.9
V
-4.0
V
V
mA
UNITS
V
Output Voltage
V
OUT
Output Voltage Range
Set Voltage
Supply Current
mVp-p
kHz
V
V
µA
pF
Note 2:
The supply voltage can drop to 4.5V, but the output may no longer sink 5mA at -4.1V.
Note 3:
The MAX852 will operate with a 50kHz to 250kHz square wave of 40% to 60% duty cycle. For best performance, use an
80kHz to 120kHz square wave with 50% duty cycle.
2
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
