TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
If this typology is not the one implemented, the user needs to
be aware that the VCC pin is not monitored for undervoltage.
LOGIC VOLTAGE (VCC) AND RESET
INTEROPERABILITY
Only the V1_FB and VB+ pins are monitored for
undervoltage. Thus, it is possible for VCC to be under voltage
The 3.3 V or 5.0 V VV1 output voltage should feed back to
the VCC input pin directly (see Figure 9) to ensure that the
34920 can be properly reset during a power-down situation.
without the 34920 issuing a reset.
VVB+ (21 V to 42 V)
34920
VCC
VB+
V1_SWITCH
VV1
V1 Regulator
V1_FB
VB+
Oscillator
V2_SWITCH
VV2
V2 Regulator
V2_FB
ENABLE
VVB+ (21 V to 42 V)
22 µF 25 V
VB
Oscillator
CP1
Vb Generator
10 nF 50 V
CP2
Figure 9. Voltage Regulator Functions
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
25
FREESCALE [ Freescale ]
