PEB2023 Datasheet, PDF (17/25 Pages) Siemens Semiconductor Group – ISDN DC Converter Circuit IDCC

PEB 2023
PEF 2023
Functional Description
Note:
An internal 9.4V zener diode protects the V_EXT input against overvoltages. The
maximum zener current is 6mA! If the external supply isn’t stabilized, the input
current must be limited (e.g. by a resistor, see also supply voltage range 0)!
Supply Voltage Ranges
Supply Voltage Range 0: 8V to 16V
In this supply voltage range the PEB/F 2023 can be supplied from a 12V battery.
Connect the positive supply voltage via a resistor (R₇ in figure 6) to pin V_EXT and pin
V_S via a resistor (R₆ in figure 6) to GND. Pin UV must be connected to pin V_S. Pin
UVx must be connected to pin V_EXT. For calculating the values of the two resistors
R₆ and R₇, see the description of figure 6.
Supply Voltage Range 1: 12V to 80V
Connect the input voltage to pin V_S and via a resistor (R₆ in figure 5) to pins UV and
UVx. For calculating the value of this resistor see the description of figure 5.
Supply Voltage Range 2: 22V to 90V
Connect the input voltage to pin V_S and via a resistor to pin UV. Pin UVx is not
connected (floating).
Supply Voltage Range 3: U_ZD+8V to U_ZD+90V
Connect the input voltage via a zener diode (minimum zener voltage U_ZD = 14V) to
pin V_S and via a resistor (R₆ in figure 4) to pin UV. Pin UVx is not connected
(floating).
Undervoltage Lockout
At the undervoltage detection pin UV, a resistor with a value of about 100kΩ..10MΩ is
required to protect this pin against high currents (see absolute maximum ratings). The
level of undervoltage detection when using supply voltage range 1 is 8V..12V, using
supply voltage range 2 or 3, it is 18V..22V. To get a higher undervoltage detection level
a zener diode in series with the resistor is required.
When the PEB/F 2023 detects an undervoltage condition, the gate output driver will be
turned off. The DC/DC conversion is disabled and the PEB/F 2023 shows a high input
impedance seen from the undervoltage detection pins (UV, UVx) and from pin V_S to
GND. Also the voltage on V_EXT will decrease. When the undervoltage condition is
removed, the DC/DC converter will be enabled once again with a soft start.
Note:
When using supply voltage range 0 the undervoltage detection circuit is not
working. The resistor connected between V_S and GND bypasses this
undervoltage detection circuit (R₆ in figure 6).
Semiconductor Group
17
08.97