RC4190
PRODUCT SPECIFICATION
The timing capacitors are set up exactly as in the voltage
dependent oscillator application of Figure 19. The values of
R2, R5, C6, and C4 that are given were chosen to optimize
for the +12V battery conditions, setting the threshold for
Negative Step-Up Regulator
In the circuit of Figure 22, a bootstrap arrangement of supply
and ground pins helps generate an output voltage more nega-
tive than the input voltage. On power-up, the output filter
oscillator frequency change at V
BAT
= +8.5V.
capacitor (C ) will charge through D2 and L . When the
F
X
voltage goes below -2.4V, the RC4190 begins switching and
charging C . The output will regulate at a value equal to the
As given, this power supply is capable of delivering +45 mA
and -15 mA with regulation, until the battery decays below
5.0V.
F
reference voltage (1.31V) plus the zener voltage of D1. R
sets the value of zener current, stabilized at 1.31V/R2.
Z
For information on adjusting the RC4391 to meet a specific
application refer to the Raytheon RC4391 data sheet.
-I OUT = -15 mA
+VBAT
(2.4 to 5V)
D2
1N914
L2
100 µH
D1
1N914
VREF
+1.25V
+I OUT = 45 mA
+VOUT
-VOUT
R1
21M
L1
50 µH
C1
150 µF
6
R2
68K
7
4
x
5
x
5
+V
s
R7
100K
CF2
330 µF
C3
200 pF
L
VREF
+V
s
L
6
3
IC
7
4
4391
4190
GND
VFB
8
VFB
R4
100K
GND
C
x
C
x
LBR
R3
27K
LBD
2
LBD
8
LBR
R7
100K
2
3
1
1
C6
40 pF
C4
40 pF
To +VOUT
C5
20 pF
R2
R5
18K
C7
20 pF
+VOUT = VREF
(
+1)
R3
R6
65-2685
-VOUT = +VOUT
(
)
R7
Figure 21. RC4190/RC4391 Power Supply (±15V)
D1
R1
1M
7
6
5
I C
4190
Gnd
VFB
+VS
R2
10K
CX
LX
3
2
4
CX
R3
R4
D2
-VOUT
Q1
CF
+
-VIN
65-4131
LX
Figure 22. Negative Step-Up Regulator
15
RAYTHEON [ RAYTHEON COMPANY ]
