Low-Noise, Regulated, -2V GaAsFET Bias
MAX840/MAX843/MAX844
ABSOLUTE MAXIMUM RATINGS
Operating Temperature Ranges
Supply Voltage, V
IN
to GND ..................................-0.3V to 10.5V
V
NEGOUT
to GND ...................................................-10.5V to 0.3V
MAX84_I_ _A ...................................................-25°C to +85°C
V
IN
to V
NEGOUT
.........................................................-0.3V to 21V
MAX84_E_ _A ..................................................-40°C to +85°C
V
OUT
to GND (Note 1).......................................V
NEGOUT
to 0.3V
Storage Temperature Range .............................-65°C to +150°C
V
SHDN
to GND ............................................-0.3V to (V
IN
+ 0.3V)
Lead Temperature (soldering, 10sec) .............................+300°C
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) .........................471mW
Note 1:
The output may be shorted to NEGOUT or GND if the package power dissipation is not exceeded. Typical short-circuit
current from 4V to GND is 40mA.
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
(Figures 2a and 2c, 2.5V
≤
V
IN
≤
10V, V
OUT
= -2V, GND = 0V, R
L
=
∞,
SHDN = V
IN
, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are measured at V
IN
= 3.6V and T
A
= +25°C.)
PARAMETER
Supply Voltage Range
SYMBOL
V
IN
V
IN
≥
2.5V,
I
OUT
= 0mA to 3mA
V
IN
≥
2.7V,
I
OUT
= 0mA to 4mA
V
IN
≥
2.5V,
I
OUT
= 0mA to 3mA
V
IN
≥
2.7V,
I
OUT
= 0mA to 4mA
CONDITIONS
MIN
2.5
-2.1
-2.1
-2.05
-2.05
-2.0
-2.0
-2.0
-2.0
-0.5 to
(V
IN
- 0.6)
MAX840, no load
MAX840, V
FB
= -0.5V
MAX843/MAX844, V
CONT
= 0V
No load, V
IN
≤
3.6V
MAX840/MAX843, V
IN
= 10V, SHDN = 0V
Shutdown Supply Current
I
SHUT
MAX844, V
IN
= 10V, SHDN = 0V
MAX844, V
IN
≤
3.6V, SHDN = 0V
V
OUT
Load Regulation
V
OUT
Ripple
Oscillator Frequency
Input High Voltage
Input Low Voltage
Input Current
Input Capacitance
2
F
OSC
V
IH
V
IL
I
IN
C
IN
V
IN
= 3.6V,
R
L
=
∞
or 500Ω
C4 = 10µF
V
IN
= 3.6V,
T
A
= +25°C
SHDN
SHDN
SHDN
SHDN
-1
10
MAX840/MAX843/
MAX844
MAX844, SHDN = 0V
80
14
2.2
0.35
1
MAX840, V
FB
= 0V
MAX843/MAX844,
V
CTRL
= 2V
940
175
3
2
1
100
20
120
26
V
V
µA
pF
300
8
8
mV/mA
mVp-p
kHz
-0.516
-0.5
±1
±1
750
-0.484
±100
±100
1300
1
µA
TYP
MAX
10
-1.9
-1.9
V
-1.95
-1.95
V
V
nA
nA
µA
UNITS
V
MAX840, V
FB
= 0V
Output Voltage
V
OUT
MAX843/MAX844,
V
CTRL
= 2V
Output Voltage Adjust Range
FB Voltage
FB Leakage Current
CONT Leakage Current
Supply Current
V
OUT
V
FB
I
FB
I
CONT
I
Q
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
