GM5510
STANDARD
VOLTAGE DETECTOR
Application Notes
1.
Please use this IC within the stated maximum ratings. Operation beyond these limits may cause degrading or
permanent damage to the device.
2.
When a resistor is connected between the VIN pin and the input with CMOS output configurations, oscillation may
occur as a result of voltage drops at RIN if load Current (IOUT) exists. (Refer to the Oscillation Description (1)
below)
3.
When a resistor is connected between the VIN pin and the input with CMOS output configurations, irrespective of
N-ch output configurations, oscillation may occur as a result of through Current at the time of voltage release
even if load Current (IOUT) does not exist. Refer to the Oscillation Description (2) below)
4.
5.
6.
With a resistor is connected between the VIN pin and the input, detect and release voltage will rise as a result of
the IC's supply current flowing through the VIN pin.
In order to stabilize the IC's operations, please ensure that VIN pin's input frequency's rise and fall times are more
than several µSec/V.
Please use N-ch open drains configuration, when a resistor RIN is connected between the VIN pin and power
source. In such casese, please ensure that RIN is less than 10kΩ and that C is more than 0.1µF
RIN
GM5510N
VIN
VOUT
VSS
C
Circuit using an input resistor
Oscillation Description
(1) Output Current oscillation with the CMOS output Configuration
When the voltage applied at IN rises, release operations commence and the detector's output voltage increases. Load
Current (IOUT) will flow at RL. Because a voltage drop (RIN x IOUT) is produced at the RIN resistor, located between the
input (IN) and the VIN pin, the load current will flow via the IC'S VIN pin. The voltage drop will also lead to a fall in the
voltage level at the VIN pin. When the VIN pin voltage level falls below the detect voltage level, detect operations will
commence. Following detect operations, load Current flow will cease and since voltage drop at RIN will disappear, the
voltage level at the VIN pin will rise and release operations will begin over again. Oscillation may occur with this
"release – detect – release" repetition.
Further, this condition will also appear via means of a Similar mechanism during detect operations.
(2) Oscillation as a result of through Current
Since the GM5510 Series are CMOS IC'S, through current will flow when the IC'S internal circuit switching operates
(during release and detect operations). Consequently, oscillation is liable to occur as a result of drops in voltage at the
through Current's resistor (RIN) during release voltage operations. (Refer to Figure 3)
Since hysteresis exists during detect operations, oscillation is unlikely to occur.
Input
Input
R
IN
R
IN
RIN X IOUT
Voltage dro
RIN X IOUT
G
M5510C
p
I
OUT
G
M5510C
Voltage drop
I
OUT
GM5510N
V
V
IN
OUT
V
V
IN
OUT
V
SS
V
SS
Include through current
Figure 2 Oscillation in relation to output current
Figure 3 Oscillation in relation to through urrent
11
GAMMA [ GAMMA MICROELECTRONICS INC. ]
