LTC1983-3/LTC1983-5
100mA Regulated
Charge-Pump Inverters
in ThinSOT
FEATURES
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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
2.3V to 5.5V Operating Voltage Range
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.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
APPLICATIO S
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–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
1983fa
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
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
●
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)
(LTC1983-5)
V
IN
Minimum 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
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)
●
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
CONDITIONS
●
MIN
3.0
5.0
2.3
–2.88
–2.88
– 4.8
TYP
MAX
5.5
5.5
UNITS
V
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
Burst Mode is a registered trademark of Linear Technology Corporation.
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
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.
1983fa
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
EFFICIENCY (%)
60
R
OUT
(Ω)
50
40
30
20
10
0
0
20
60
40
I
OUT
(mA)
T
A
= 25°C
80
100
1983 G01
V
IN
= 2.3V
V
IN
= 3.3V
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
–2.3
75
EFFICIENCY (%)
V
OUT
(V)
V
IN
= 5V
50
–2.7
80°C
–2.9
–3.1
–3.3
–40°C, 0°C, 40°C
V
OUT
(–V)
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)
I
IN
(mA)
4.3
4.1
3.9
3.7
3.5
–40
V
IN
= 5V
4.5
I
IN
(µA)
60
10
TEMPERATURE (°C)
U W
V
IN
= 5V
1983 GO4
Output Impedance vs
Input Voltage
12.5
12.0
11.5
11.0
20
I
OUT
= 25mA
T
A
= 25°C
25
30
Output Impedance
vs I
OUT
(LTC1983-5)
T
A
= 25°C
V
IN
= 2.3V
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
3.2
120°C
–2.5
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
100
40
60
80
OUTPUT CURRENT (mA)
120
1983 G06
Open-Loop Input Current
vs V
IN
(LTC1983-5)
T
A
= 25°C
4.0
3.5
3.0
2.5
2.0
1.5
50
45
40
35
30
25
20
15
2.3
2.8
3.3
3.3
V
IN
(V)
4.3
4.8
1983 G09
Burst Mode Current
vs Temperature (LTC1983-3)
V
IN
= 5V
110
1983 G07
10
–40
10
60
110
1983 G08
TEMPERATURE (°C)
1983fa
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
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)
T
A
= 25°C
18
16
14
V
THRESHOLD
(V)
12
10
8
6
4
2
0
–50
0
100
TEMPERATURE (°C)
50
150
1983 G11
SHDN Pin Input Current
vs Temperature
3.5
3.0
2.5
I
SHDN
(µA)
R
OUT
(Ω)
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
0.9
0.8
V
IN
= 3V
0.7
0.6
0.5
0.4
0.3
0.2
0.1
SHDN Pin Threshold Voltage
vs Temperature
V
IN
= 5V
0
–50
0
50
100
TEMPERATURE (°C)
150
1983 G12
R
OUT
vs C
FLY
(V
IN
= 5V)
1400
1200
1000
800
600
400
200
0
0.01
V
IN
5V
V
IN
= 5V
T
A
= 25°C
V
OUT
1V
V
OUT
Start-Up into 100mA
Resistive Load
50µs/DIV
1983 G15
150
0.1
C
FLY
(µF)
1
1983 G14
V
OUT
Ripple at 30mA Load
V
OUT
20mV
V
OUT
20mV
V
OUT
Load Step Reponse from
I
OUT
= 0 to I
OUT
= 100mA
I
OUT
100mA
2.5µs/DIV
100µs/DIV
1983 G16
1983 G17
1983 G18
1983fa
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
1983fa
5
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