PEB2023 Datasheet, PDF (13/25 Pages) Siemens Semiconductor Group – ISDN DC Converter Circuit IDCC

For calculation of resistor R₇:
V_IN, input voltage :
V_EXT :
I_R7, input current :
V_INmin = 8V,
V_EXTmin = 6V,
I_R7min = 1mA,
V_INmax = 16V
V_EXTmax = 9V
I_R7max = 6mA
PEB 2023
PEF 2023
Overview
R_7min
=
V-----_{I--N----m----a--x----–-----V----E---X----T---m----a---x}
I_R7max
=
1, 667kΩ
R_7max
=
V-----_{I--N----m----i-n----–-----V----E----X---T----m----i-n-}
I_R7min
=
2kΩ
To get lower power dissipation the value of resistor R₇ should also be as high as
possibile. For this reason we use R_7max. If in the calculation above R_7min is higher than
R_7max, then the input voltage range is not correct; V_INmax-V_INmin is too large.
Note: If V_INmin = 6V and V_INmax = 9V then the resistor R₇ is not necessary. The input
voltage V_IN can directly be connected to V_EXT.
8 ... 16 V
4.7µF
R₆
1ΜΩ/10%
R₇
2ΚΩ/1%
20%
C_{4 +}
0.47µF
20%
R₅
0.1Ω/5%
N1
C_{5 +}
T₁
BSP 295
C₆ +
100µF
20%
7 11 12 5 6 2 4
V_S UV UVx V_EXT C_SS I_P GA
PEB 2023
PEF 2023
GND RC ^VREF ^VP SYNC COMP ^VN
3 14 1 9 13 8 10
0V
R₁
39ΚΩ
5%
C₁
1nF
5%
R₂
47ΚΩ/5%
+ _C3
1µF
20%
C₂
100nF
10%
R₃
18ΚΩ/1%
R₄
72ΚΩ/1%
BYS 21-45
D₁
C_L1 ⁺
N2a _220µF
20%
+5V
R_Load1
82Ω/1%
AAAA ^{0 V}
C_L2 ⁺
N2b _68µF
20%
D₂
BAS 21
R_Load2
3.9ΚΩ/1%
- 42 V
BYS 21-45
D₃
C_L3 ⁺
N2c _100µF
20%
R_Load3
130Ω/1%
2.2 V
Figure 6
PEB/F 2023 in a non-isolated Flyback Configuration
Semiconductor Group
13
08.97