ncv8504pwadjr2 ON Semiconductor, ncv8504pwadjr2 Datasheet - Page 9

• Manufacturer Part Number: ncv8504pwadjr2
• Description: 2.5v, 3.3v, 5.0v, Adjustable/400ma Ldo W/ Reset, Delay, Adjustable Reset, Early Warning
• Manufacturer: ON Semiconductor

control function RESET (Figure 13).
RESET Function
powers up until V
voltage, or when V
than 4.0% below the regulated output voltage. Hysteresis is
included in the function to minimize oscillations.
controlled by a low voltage detection circuit. The circuit is
functionally independent of the rest of the IC thereby
guaranteeing that the RESET signal is valid for V
as 1.0 V.
Adjustable Reset Function
external resistor divider to the R
lead, as displayed in Figure 14. This lead is grounded to
select the default value of 4.6 V (on the 5.0 V option).
DELAY Function
external capacitor) delay on the RESET output lead.
DELAY
V
V
RESET
V
R(ADJ)
The NCV8504 contains the microprocessor compatible
OUT
A RESET signal (low voltage) is generated as the IC
The RESET output is an open collector NPN transistor,
The reset threshold can be made lower by connecting an
The reset delay circuit provides a programmable (by
IN
Figure 13. Reset and Delay Circuit Wave Forms
REGULATOR CONTROL FUNCTIONS
R
ADJ
DELAY
T
Figure 14. Adjustable RESET
d
NCV8504
OUT
OUT
C
DELAY
is within 1.5% of the regulated output
RESET
drops out of regulation,and is lower
V
OUT
T
d
ADJ
R
RST
lead from the V
CIRCUIT DESCRIPTION
OUT
C
OUT
to μP and
System
Power
to μP and
RESET
Port
NCV8504 Series
Threshold
Threshold
http://onsemi.com
as low
RESET
DELAY
OUT
(V
DT
)
9
to the external DELAY capacitor during the following
proceedings:
FLAG/Monitor Comparator
terminal is tied to the on-chip bandgap voltage reference.
This provides a very temperature stable referenced
comparator with versatile use in any system. The trip point
can be programmed externally using a resistor divider to the
input monitor (MON) (Figure 15). The typical threshold is
1.29 V on the MON pin.
Voltage Adjust
output voltage. The feedback to the V
a voltage divider referenced to the output voltage. The loop
is balanced around the Unity Gain threshold (1.30 V
typical).
V
V
MON
BAT
The DELAY lead provides source current (typically 4.0 μA)
A general use comparator is included whose positive input
Figure 16 shows the device setup for a user configurable
1. During Power Up (once the regulation threshold
2. After a reset event has occurred and the device is
has been verified).
back in regulation. The DELAY capacitor is
discharged when the regulation (RESET threshold)
has been violated. This is a latched incident. The
capacitor will fully discharge and wait for the
device to regulate before going through the delay
time event again.
Figure 15. Flag/Monitor Function
NCV8504
Figure 16. Adjustable Output
V
MON
DELAY
R
IN
ADJ
V
V
NCV8504
OUT
ADJ
RESET
GND
Voltage
FLAG
V
OUT
1.28 V
15 k
5.1 k
ADJ
≈5.0 V
C
pin is taken from
OUT
C
OUT
V
RESET
I/O
CC
μP