LTC1983-3/LTC1983-5
100mA Regulated
Charge-Pump Inverters
in ThinSOT
FEATURES
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Fixed Output Voltages: –3V, –5V or Low Noise V
IN
to –V
IN
Inverted Output
±4%
Output Voltage Accuracy
Low Quiesient Current: 25µA
100mA Output Current Capability
3V to 5.5V Operating Voltage Range (LTC1983-3)
2.3V to 5.5V Operating Voltage Range (LTC1983-5)
Internal 900kHz Oscillator
“Zero Current” Shutdown
Short-Circuit and Over-Temperature Protected
Low Profile (1mm) ThinSOT
TM
Package
The LTC
®
1983-3 and LTC1983-5 are inverting charge
pump DC/DC converters that produce negative regulated
outputs. The parts require only three tiny external capaci-
tors and can provide up to 100mA of output current. The
devices can operate in open loop mode (creating a –V
IN
supply) or regulated output mode depending on the input
supply voltage and the output current.
The LTC1983-3/LTC1983-5 have many useful features for
portable applications including very low quiescent current
(25µA typical) and a zero current shutdown mode pro-
grammed through the SHDN pin.
The LTC1983-3/LTC1983-5 are over-temperature and
short-circuit protected. The parts are available in a 6-pin
low profile (1mm) ThinSOT package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
–3V Generation in Single-Supply Systems
Portable Equipment
LCD Bias Supplies
GaAs FET Bias Supplies
TYPICAL APPLICATIO
–3V at 100mA DC/DC Converter
V
IN
3V TO 5.5V
C
IN
10µF
OFF ON
V
IN
V
OUT
V
OUT
= –3V
I
OUT
= UP TO 100mA
C
OUT
10µF
V
OUT
(V)
–3.3
–3.2
–3.1
–3.0
–2.9
LTC1983-3
SHDN
C
+
GND
C
–
1983-3 TA01
C
FLY
1µF
C
FLY
: TAIYO YUDEN LMK212BJ105
C
IN
, C
OUT
: TAIYO YUDEN JMK316BJ106ML
–2.8
–2.7
0
20
U
V
OUT
vs I
OUT
V
IN
= 5V
V
IN
= 3.3V
40
60
I
OUT
(mA)
80
100
1983 TA02
U
U
sn1983 1983fs
1
LTC1983-3/LTC1983-5
ABSOLUTE
(Note 1)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
V
CC
1
V
OUT
2
C
+
3
6 SHDN
5 GND
4 C
–
V
IN
to GND ................................................... –0.3V to 6V
SHDN Voltage .............................................. –0.3V to 6V
V
OUT
to GND (LTC1983-3) .................. 0.2V to V
OUT
Max
V
OUT
to GND (LTC1983-5) .................. 0.2V to V
OUT
Max
I
OUT
Max ............................................................. 125mA
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range (Note 2) ...–40°C to 85°C
Storage Temperature Range ................. – 65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
LTC1983ES6-3
LTC1983ES6-5
S6 PART
MARKING
LTPC
LTYB
S6 PACKAGE
6-LEAD PLASTIC SOT-23
T
JMAX
= 125°C,
θ
JA
= 256°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V, C
FLY
= 1µF, C
OUT
= 10µF
unless otherwise noted.
PARAMETER
V
IN
Operating Voltage (Regulated Output Mode) (LTC1983-3)
V
IN
Min Startup Voltage
V
OUT
(LTC1983-3)
V
OUT
(LTC1983-5)
V
IN
Operating Current
V
IN
Operating Current (Open-Loop Mode) (LTC1983-5)
V
IN
Shutdown Current
Output Ripple
Open-Loop Output Impedance (LTC1983-3): R
OUT
Open-Loop Output Impedance (LTC1983-5): R
OUT
Oscillator Frequency
SHDN Input High
SHDN Input Low
SHDN Input Current
Burst Mode is a registered trademark of Linear Technology
Corporation.
Note 1:
Absolute Maximum Ratings are those values beyond
which the life of a device may be impaired.
V
SHDN
= 5.5V
V
IN
≥
3.3V, I
OUT
≤
25mA
V
IN
≥
5V, I
OUT
≤
100mA
V
IN
≥
5V, V
IN
–5V
≥
I
OUT
• R
OUT
V
IN
≤
5.5V, I
OUT
= 0µA, SHDN = V
IN
V
IN
= 3.3V
V
IN
= 4.75V
SHDN = 0V, V
IN
≤
5.5V
3.3
≤
V
IN
≤
5.5
V
IN
= 3.3V, V
OUT
= –3V
V
IN
= 3.3V, I
OUT
≈
50mA
V
IN
= 5V, I
OUT
≈
60mA
(Non-Burst Mode
®
Operation)
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
q
q
q
q
q
MIN
3.0
2.3
–2.88
–2.88
– 4.8
TYP
MAX
5.5
UNITS
V
V
V
V
V
µA
mA
mA
–3
–3
–5
25
2.5
4
0.1
60
11
11
8.5
900
–3.12
–3.12
– 5.2
60
1
mV
P-P
Ω
Ω
Ω
kHz
V
0.3
V
µA
1.1
2.2
4
Note 2:
The LTC1983E-3/LTC1983E-5 are guaranteed to meet
performance specifications from 0°C to 70°C. Specifications over the
– 40°C to 85°C operating temperature range are assured by design,
characterization and correlation with statistical process controls.
sn1983 1983fs
2
U
µA
W
U
U
W W
W
LTC1983-3/LTC1983-5
TYPICAL PERFOR A CE CHARACTERISTICS
Efficiency vs I
OUT
(LTC1983-5)
90
80
70
V
IN
= 2.3V
V
IN
= 5V
V
IN
= 3.3V
R
OUT
(Ω)
EFFICIENCY (%)
60
50
40
30
20
10
0
0
20
60
40
I
OUT
(mA)
T
A
= 25°C
80
100
1983 G01
10.5
10.0
9.5
9.0
8.5
8.0
2.35
R
OUT
R
OUT
(Ω)
Efficiency vs I
OUT
100
V
OUT
= –3V
T
A
= 25°C
–2.1
V
IN
= 3.3V
75
EFFICIENCY (%)
–2.7
80°C
–2.9
–3.1
–3.3
–40°C, 0°C, 40°C
V
OUT
(–V)
V
OUT
(V)
50
25
0
0.01
0.1
1
I
OUT
(mA)
10
Open-Loop Current
vs Temperature (LTC1983-5)
4.9
4.7
4.5
I
IN
(mA)
V
IN
= 5V
I
IN
(mA)
I
IN
(µA)
4.3
4.1
3.9
3.7
3.5
–40
60
10
TEMPERATURE (°C)
U W
V
IN
= 5V
1983 GO4
Output Impedance vs
Input Voltage
12.5
12.0
11.5
11.0
I
OUT
= 25mA
T
A
= 25°C
Output Impedance
vs I
OUT
(LTC1983-5)
30
T
A
= 25°C
V
IN
= 2.3V
25
20
15
V
IN
= 3.3V
10
V
IN
= 5V
5
3.35
V
IN
(V)
4.35
5.35
1983 TA02
0
20
60
40
I
OUT
(mA)
80
100
1983 G03
–3V
OUT
vs I
OUT
Over Temperature
3.3
–3V
OUT
vs I
OUT
Over Temperature
(V
IN
= 5V)
V
IN
= 5V
–2.3
120°C
–2.5
3.2
3.1
–40°C 0°C
3.0
40°C
2.9
80°C
2.8
2.7
100
–3.5
0
20
80
60
100
40
OUTPUT CURRENT (mA)
120
1983 G05
0
20
40
60
80
100
OUTPUT CURRENT (mA)
120
1983 G06
Open-Loop Input Current
vs V
IN
(LTC1983-5)
4.5
T
A
= 25°C
4.0
3.5
3.0
2.5
2.0
1.5
50
45
40
35
30
25
20
15
Burst Mode Current
vs Temperature (LTC1983-3)
V
IN
= 5V
110
1983 G07
2.3
2.8
3.3
3.3
V
IN
(V)
4.3
4.8
1983 G09
10
–40
10
60
110
1983 G08
TEMPERATURE (°C)
sn1983 1983fs
3
LTC1983-3/LTC1983-5
TYPICAL PERFOR A CE CHARACTERISTICS
Burst Mode Input Current
vs V
IN
(LTC1983-3)
31.0
30.5
30.0
T
A
= 25°C
18
16
14
V
THRESHOLD
(V)
INPUT CURRENT (µA)
29.5
29.0
28.5
28.0
27.5
27.0
26.5
3.1
3.6
4.6
4.1
V
IN
(V)
5.1
5.5
R
OUT
(Ω)
SHDN Pin Input Current
vs Temperature
3.5
3.0
2.5
1400
1200
1000
R
OUT
(Ω)
I
SHDN
2.0
1.5
1.0
0.5
0
–50
0
100
TEMPERATURE (°C)
50
V
OUT
Ripple at 100mA Load
V
OUT
20mV
1µs/DIV
4
U W
1983 G10
1983 G13
R
OUT
vs Temperature
(I
OUT
= 10mA)
1.0
I
OUT
= 10mA
SHDN Pin Threshold Voltage
vs Temperature
0.9
0.8
12
10
8
6
4
2
0
–50
0
V
IN
= 3V
0.7
0.6
0.5
0.4
0.3
0.2
0.1
V
IN
= 5V
100
TEMPERATURE (°C)
50
150
1983 G11
0
–50
0
50
100
TEMPERATURE (°C)
150
1983 G12
R
OUT
vs C
FLY
(V
IN
= 5V)
V
IN
= 5V
T
A
= 25°C
V
OUT
Start-Up into 100mA
Resistive Load
V
OUT
1V
800
600
400
200
0
0.01
V
IN
5V
50µs/DIV
1983 G15
150
0.1
C
FLY
(µF)
1
1983 G14
V
OUT
Ripple at 30mA Load
V
OUT
Load Step Reponse from
I
OUT
= 0 to I
OUT
= 100mA
V
OUT
20mV
V
OUT
20mV
I
OUT
100mA
2.5µs/DIV
100µs/DIV
1983 G16
1983 G17
1983 G18
sn1983 1983fs
LTC1983-3/LTC1983-5
PI FU CTIO S
V
IN
(Pin 1):
Charge Pump Input Voltage. May be between
2.3V and 5.5V. V
IN
should be bypassed with a
≥4.7µF
low
ESR capacitor as close as possible to the pin for best
performance.
V
OUT
(Pin 2):
Regulated Output Voltage for the IC. V
OUT
should be bypassed with a
≥4.7µF
low ESR capacitor as
close as possible to the pin for best performance.
C
+
(Pin 3):
Charge Pump Flying Capacitor Positive Termi-
nal. This node is switched between V
IN
and GND (It is
connected to V
CC
during shutdown).
C
–
(Pin 4):
Charge Pump Flying Capacitor Negative Termi-
nal. This node is switched between GND and V
OUT
(It is
connected to GND during shutdown).
GND (Pin 5):
Signal and Power Ground for the 6-Pin
SOT-23 package. This pin should be tied to a ground plane
for best performance.
SHDN (Pin 6):
Shutdown. Grounding this pin shuts down
the IC. Tie to V
IN
to enable. This pin should not be pulled
above the V
IN
voltage or below GND.
BLOCK DIAGRA
C
+
C
FLY
1µF
C
–
CLOCK2
CHARGE PUMP
C
OUT
10µF
COMP1
1µA
–
V
OUT
S2B
+
W
U
U
U
LTC1983-X
V
IN
C
IN
10µF
S1A
S2A
CLOCK1
SHDN
CONTROL
LOGIC
S1B
V
REF
1983 BD
sn1983 1983fs
5
Talking
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