Notes on Use
1. When a resistor is connected between the V
IN
pin and the input with CMOS output configurations, oscillation may
occur as a result of voltage drops at R
IN
if load current (I
OUT
) exists.
(Refer to N.B 1- (1) below)
2. When a resistor is connected between the V
IN
pin and the input with CMOS output configurations, irrespective of
Nch output configurations, oscillation may occur as a result of through current at the time of voltage release even if
load current (I
OUT
) does not exist.
(Refer to N.B 1- (2) below)
3. With a resistor connected between the V
IN
pin and the input, detect and release voltage will rise as a result of the
IC's supply current flowing through the V
IN
pin.
4. In order to stabilise the IC's operations, please ensure that V
IN
pin's input frequency's rise and fall times are more
than several µ sec/ V.
R
IN
GM5510N
V
IN
V
OUT
V
SS
C
Diagram: Circuit using an input resistor
N. B.
1. Oscillation
(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 (I
OUT
) will flow at R
L
. Because a voltage drop (R
IN
x I
OUT
) is produced at the R
IN
resistor, located
between the input (I
N
) and the V
IN
pin, the load current will flow via the IC's V
IN
pin. The voltage drop will also
lead to a fall in the voltage level at the V
IN
pin. When the V
IN
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
R
IN
will disappear, the voltage level at the V
IN
pin will rise and release operations will begin over again.
Oscillation may occur with this "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 (R
IN
) during release voltage operations. (Refer to diagram2)
Since hysteresis exists during detect operations, oscillation is unlikely to occur.
Input
Input
R
IN
R
IN
X I
OUT
Voltage drop
V
IN
R
IN
GM5510C
V
OUT
I
OUT
GM5510N
GM5510C
V
IN
V
OUT
V
SS
V
SS
I
SS
*
(Includes through current)
GM5510
7
R
IN
X I
SS
*
Voltage drop
GAMMA [ GAMMA MICROELECTRONICS INC. ]
