CA1524 Datasheet, PDF (10/16 Pages) Intersil Corporation – Regulating Pulse Width Modulator

CA1524, CA2524, CA3524
S_A//S_B
-
+
R1
R2
RS
5
SENSE
4
V_O = 5V
( ) ^{IMAX =}
I
R_S
V_TH +
V_OR₂
R1 + R2
I_SC =
V_TH
R_S
WHERE
V_TH = 200mV
FIGURE 14. FOLDBACK CURRENT-LIMITING CIRCUIT USED
TO REDUCE POWER DISSIPATION UNDER
SHORTED OUTPUT CONDITIONS
D1
V+
S_A
S_B
+V_O
V+ > V_O
D1
V+
S_A
S_B
D1
V+
S_A
S_B
+V_O
V+ < V_O
-V_O
| V+ | > | V_O |
TABLE 1. INPUT vs. OUTPUT VOLTAGE, AND FEEDBACK
RESISTOR VALUES FOR I_L = 40mA (FOR CAPACI-
TOR-DIODE OUTPUT CIRCUIT IN FIGURE 18)
V_O (V)
-0.5
R₂ (KΩ)
6
V+ (Min.) (V)
8
-2.5
10
9
-3
11
10
-4
13
11
-5
15
12
-6
17
13
-7
19
14
-8
21
15
-9
23
16
-10
25
17
-11
27
18
-12
29
19
-13
31
20
-14
33
21
-15
35
22
-16
37
23
-17
39
24
-18
41
25
-19
43
26
-20
45
27
V+
V_O
NOTE: Diode D1 Is Necessary To Prevent Reverse
Emitter-Base Breakdown of Transistor Switch S_A.
FIGURE 15. CAPACITOR-DIODE COUPLED VOLTAGE
MULTIPLIER OUTPUT STAGES
S_A/S_B
V+
+V_O
V+ > V_O
V+
S_A/S_B
S_A/S_B
V+
+V_O
V+ < V_O
-V_O
| V+ | < | V_O |
S_A-B
FLYBACK
S_A
V+
S_B
PUSH-PULL
+
V_O
S_A
V+
S_B
-
V+
+
- ^VO
V_O
CAN BE S_A OR
S_A CAN DRIVEQ1
Q1
CAN BE S_B OR
S_B CAN DRIVEQ2
Q2
FIGURE 16. SINGLE-ENDED INDUCTOR CIRCUITS WHERE THE
TWO OUTPUTS OF THE 1524 ARE CONNECTED IN
PARALLEL
FULL BRIDGE
FIGURE 17. TRANSFORMER-COUPLED OUTPUTS
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