ICL7663SACBAZA-T Intersil, ICL7663SACBAZA-T Datasheet - Page 7

• Manufacturer Part Number: ICL7663SACBAZA-T
• Description: IC VOLT REG POS LO PWR 8-SOIC
• Manufacturer: Intersil

Specifications of ICL7663SACBAZA-T

• Reference Type: Series, Adjustable
• Voltage - Output: 1.29 ~ 16 V
• Tolerance: ±1%
• Temperature Coefficient: 100ppm/°C
• Voltage - Input: 1.6 ~ 16 V
• Number Of Channels: 1
• Current - Quiescent: 10µA
• Current - Output: 40mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Cathode: -

High output currents can be obtained only as far as package
dissipation allows. It is strongly recommended that output
current-limit sensing be used in such cases.
Current-Limit Sensing - The on-chip comparator (C in the
Functional Diagram) permits shutdown of the regulator
output in the event of excessive current drain. As Figure 8
shows, a current-limiting resistor, R
with V
load side of R
enough to produce a voltage drop equal to V
voltage feedback is by-passed and the regulator output will
be limited to this current. Therefore, when the maximum load
current (I
obtain the value for R
V
Logic-Controllable Shutdown - When equipment is not
needed continuously (e.g., in remote data-acquisition
systems), it is desirable to eliminate its drain on the system
until it is required. This usually means switches, with their
unreliable contacts. Instead, the ICL7663S can be shut
down by a logic signal, leaving only I
drain on the power source. Since this pin must not be left
open, it should be tied to ground if not needed. A voltage of
less than 0.3V for the ICL7663S will keep the regulator ON,
and a voltage level of more than 1.4V but less than V+
turn the outputs OFF. If there is a possibility that the control
signal could exceed the regulator input (V+
from this signal should be limited to 100µA maximum by a
high value (1MΩ) series resistor. This situation may occur
when the logic signal originates from a system powered
separately from that of the regulator.
Additional Circuit Precautions - This regulator has poor
rejection of voltage fluctuations from AC sources above
10Hz or so. To prevent the output from responding (where
this might be a problem), a reservoir capacitor across the
load is advised. The value of this capacitor is chosen so that
OUT
I
FIGURE 8. POSITIVE REGULATOR WITH CURRENT LIMIT
CL
V
IN
=
=
OUT2
R
LOAD
2
V
R
R
+ R
CL
CL
1
and the SENSE terminal is connected to the
0.047µF
CL
1
) is determined, simply divide V
= 25mA
. When the current through R
V
SET
V+
GND
CL
IN
= 5V
.
SENSE
V
V
SHDN
OUT2
OUT1
V
V
SET
TC
7
604kΩ
210kΩ
20Ω
R
CL
CL
Q
, is placed in series
(under 4µA) as a
R
R
2
1
IN
CL
) the current
CL
CL
(0.5V) the
10µF V
by I
is high
C
L
LOAD
+5V
IN
OUT
will
to
ICL7663S
Where:V
V
TCV
the regulated output voltage reaches 90% of its final value in
20ms. From:
In addition, where such a capacitor is used, a current-limiting
resistor is also suggested (see “Current-Limit Sensing”).
Producing Output Voltages with Negative Temperature
Coefficients -The ICL7663S has an additional output which
is 0.9V relative to GND and has a tempco of +2.5mV/°C. By
applying this voltage to the inverting input of amplifier A (i.e.,
the V
produced. The TC of the output voltage is controlled by the
R
Applications
Boosting Output Current with External Transistor
The maximum available output current from the ICL7663S is
40mA. To obtain output currents greater than 40mA, an
external NPN transistor is used connected as shown in
Figure 10.
EQ. 1: V
EQ. 2:
I =
TC
2
FIGURE 10. BOOSTING OUTPUT CURRENT WITH EXTERNAL
FIGURE 9. GENERATING NEGATIVE TEMPERATURE
/R
V
IN
TC
C
= 0.9V
3
SET
ratio (see Figure 9 and its design equations).
∆V
= +2.5mV/°C
∆t
OUT
SET
TC V
pin), output voltages having negative TC may be
,C
= V
10µF
= 1.3V
COEFFICIENTS
TRANSISTOR
OUT
+
-
I
V
OUT
SET
TC
=
R
R
=
1
3
(
V+
GND
V
(20 x 10
0.9V
1 +
SET
-
IN
+
-
R
R
V
SENSE
V
V
R
R
2
3
REF
SHDN
+
OUT
-
OUT1
OUT2
V
2
1
SET
(TC V
)
-3
R
+
)
2
= 0.022
R
R
100Ω
TC
2
3
210kΩ
) in mV/°C
604kΩ
(V
SET
V
I
EXTERNAL PIN
POWER
TRANSISTOR
0.47Ω
OUT
OUT
- V
V
TC
V
OUT
+5V
OUT
)
July 21, 2005
FN3180.5