Voltage detectors bd52xxg/fve bd53xxg/fve – Rainbow Electronics BD5323G_FVE User Manual
Page 9
Establishment of RESET transfer delay time
• Delay time at the rise of V
DD
T
PLH
: Time until when V
OUT
is 1/2 of V
DD
after the rise of V
DD
, and beyond
the release voltage (V
DET
+ V
DET
).(See P7).
Delay time T
PLH
at the rise of V
DD
can be established by C
CT
connected to C
T
pin.
9/15
Voltage detectors
BD52XXG/FVE
BD53XXG/FVE
Expression (When the threshold voltage of next inverter connected to C
T
pin is 1/2 of V
DD
.)
• Delay time at the fall of V
DD
T
PHL
: Time until when V
OUT
is 1/2 of V
DD
after across the detection voltage (Vs).
Fig.24 Delay time I/O condition
0.001
0.01
Dela
y time (msec)
CAPA ( F)
0.1
1
0.0001
0.001
0.01
0.1
1
10
100
1000
10000
Fig.22
Delaly time(T
PLH
) and external capacitance
Fig.22 shows the relation between capacity of external
capacitor and delay time T
PLH
.
T
PLH
=0.69XC
CT
XR
CT
C
CT
: C
T
pin external capacitor
R
CT
: C
T
pin internal impedance
ex) When C
T
external capacitor is 0.047 F,
T
PLH
=0.69X0.047 FX9M
=292ms
Fig.23
Vout
Reset
R
L
C
L
V
DD
GND
CT
ICT
Vref
IOL
Release voltage
V
DET
[V]
0.5V
T
PLH
0.5V
5V
V
DD
Release voltage
(V
DET
+ V
DET
)
V
OUT
V
OUT
=5V X 0.5 [V]
T
PHL
T
PHL
=T
A
+T
B
+T
C
T
A
=
C
L
X V
DET
: Delay time by external C
L
, R
L
I
OL
C
L :
Capacity of external capacitor beween V
OUT
pin and GND
V
DET :
Detection voltage
I
OL :
"L" output current
Make sure to test in actual because it depends on detection voltage.
Reference : V
DET
=2.4V, V
DD
=2.4V About 5mA : typ.
T
B
=
C
T
X
V
DET
: Delay time by external C of CT pin
I
CT
CT : External capacitor between CT pin and GND
T
C
= About 20.9 s(Typ.)IC internal transfer delay time
V
DET
: Detection voltage
I
CT
: Output current of CT pin
(typ.)
Rev.A