Datasheet

UNISONIC TECHNOLOGIES CO., LTD
LC1111
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LINEAR INTEGRATED CIRCUIT
LOW DROPOUT LINEAR
REGULATOR CONTROLLER

DESCRIPTION
6
The UTC LC1111 is a low dropout linear regulator controller for
applications requiring high-current and ultra low dropout voltages.
The use of an external N-Channel MOSFET and provide an
adjustable output by using an external resistive divider.
An extremely accurate 0.8V (±2%) reference allows the
implementation of sub 1 V voltage supplies. The reference is
guaranteed over the complete supply and temperature ranges.
The UTC LC1111 integrates various functions. For example, a
Power-On-Reset (POR) circuit monitors VCC supply voltage to
prevent wrong operations; the function of Under-Voltage
Protection (UVP) protects the device from short circuit condition.
The soft-start of output voltage is adjustable by the external
capacitor on SS pin. Moreover, the UTC LC1111 can be enabled
by other power system; namely, holding the EN above 1.6V
enables output and pulling the EN under 0.4 disables output.
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5
4
1
2
3
SOT-26
FEATURES
* 4.5V~13.5V supply voltage range
* 0.8V (±2%) voltage reference (temperature and process)
* Power-On-Reset monitoring on VCC
* Fast transient response
* Programmable soft-start
* Enable control function
* Low shutdown current
* Under-Voltage protection
* Two versions of IC available: UVP activated after VOUT is ready

ORDERING INFORMATION
Ordering Number
LC1111G-AG6-R
www.unisonic.com.tw
Copyright © 2015 Unisonic Technologies Co., Ltd
Package
SOT-26
Packing
Tape Reel
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QW-R102-072.a
LC1111
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MARKING
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PIN CONFIGURATION
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PIN DESCRIPTION
PIN NO.
PIN NAME
1
EN
2
GND
3
FB
4
5
SS
DRV
6
VCC
LINEAR INTEGRATED CIRCUIT
DESCRIPTION
Enable control pin. Pulling the EN high (VEN>1.6) enables the VOUT; forcing the EN
low (VEN<0.4V disables the VOUT. When re-enabled, the IC undergoes a new
soft-start process. The EN pin is pulled high internally, hence it can be left open if the
EN control is not used.
Ground pin of the circuitry. All voltage levels are measured with respect to this pin.
Voltage Feedback Pin. Connecting this pin to an external resistor divider receives the
feedback voltage of the regulator.
Connect this pin to a capacitor for soft-start.
This pin drives the gate of an external N-channel MOSFET for linear regulator.
Power input pin of the device. The voltage at this pin is monitored for
Power-On-Reset purpose.
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LC1111
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LINEAR INTEGRATED CIRCUIT
BLOCK DIAGRAM
Power-On
Reset
VCC
Enable_EA
Internal
Regulator
POR
VP
VP
+
+
-
0.8V
Error
Amplifier
5µA
EN
+
Enable
-
DRV
Control
Logic
0.8V
FB
-
VP
UV
4.5µA
SS
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+
UVP
Comparator
70%VREF
GND
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LC1111
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LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
VCC Input Voltage (VCC to GND)
VCC
-0.3~16
V
EN, SS, to GND Voltage
-0.3~7
V
FB to GND Voltage
VFB
-0.3~7
V
DRV to GND Voltage
VDRV
-0.3~VCC+0.3
V
Junction Temperature
TJ
150
°C
Storage Temperature
TSTG
-65~150
°C
Maximum Lead Soldering Temperature, 10 Seconds
TSDR
260
°C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

THERMAL CHARACTERISTIC
PARAMETER
Junction-to-Ambient Resistance in Free Air (Note 1)

SYMBOL
θJA
TYPICAL VALUE
250
UNIT
°C/W
RECOMMENDED OPERATING CONDITIONS (Note 2)
PARAMETER
SYMBOL
RATINGS
UNIT
VCC Input Voltage (VCC to GND)
VCC
4.5~13.5
V
EN to GND Voltage
VEN
0~5.5
V
VOUT Output Voltage (Note 3)
VOUT
0.8~VIN-VDROP
V
Ambient Temperature
TA
-40~85
°C
Junction Temperature
TJ
-40~125
°C
Notes: 1. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air.
2. Refer to the typical application circuit.
3. VDROP defined as the VIN -VOUT voltage at VOUT=98% normal VOUT. The linear regulator must provide the
output MOSFET with sufficient Gate-to-Source voltage (VGS=VCC-VOUT) to regulate the output voltage.
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LC1111
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LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, these specifications apply over VCC=5/12V, TA=-40~85°C. Typical values are at
TA=25°C.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
SUPPLY CURRENT
VCC=12V
0.8
1.0
VCC Supply Current
ICC
VCC=5V
0.8
1.0
VCC=12V, EN=GND
5
VCC Shutdown Current
ISD
VCC=5V, EN=GND
5
POWER-ON-RESET (POR)
VCC POR Threshold
VCC Risig
3.8
4.0
4.2
VCC POR Hysteresis
0.4
REFERENCE VOLTAGE
Reference Voltage
VREF VCC=12V, TA=25°C
0.8
Reference Voltage Accuracy
VCC=12V
-1
1
Line Regulation
VCC=4.5V~13.2V
-1.5
1.5
FB Input Current
-100
100
ERROR AMPLIFIER
Unity Gain Bandwidth
VCC=5/12V
2
Open Loop DC Gain
VCC=12V, No Load
60
80
Power Supply Rejection Ratio
PSRR VCC=12V, 100Hz, No Load
50
VCC=12V, IDRV (SOURCE)=5mA, VFB=0.6V 11.2
11.5
DRV High Voltage
VDRV (high)
VCC=5V, IDRV (SOURCE)=5mA, VFB=0.6V
4.7
VCC=12V, IDRV (SINK)=5mA, VFB=1V
0.5
1
DRV Low Voltage
VDRV (low)
VCC=5V, IDRV (SINK)=5mA, VFB=1V
0.8
VCC=12V, VDRV=6V, VFB=0.6V
50
DRV Source Current
IDRV (source)
VCC=5V, VDRV=2.5V, VFB=0.6V
10
VCC=12V, VDRV=6V, VFB=1V
40
DRV Sink Current
IDRV (sink)
VCC=5V, VDRV=2.5V, VFB=1V
10
ENABLE
EN Logic High Threshold
VEN (TH) VEN Rising
0.55
0.8
1.05
Voltage
EN Hysteresis
50
EN Shutdown Debounce
VEN Falling
2
EN Internal Pull High Current
5
SOFT-START
SS Current
ISS
4.5
UNDER-VOLTAGE PROTECTION (UVP)
Under-Voltage Threshold
VUV (TH) VEN=5V, VFB Falling
68
75
82
UVP Debounce Interval
5
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
UNIT
mA
mA
µA
µA
V
V
V
%
%
nA
MHz
dB
dB
V
V
V
V
mA
mA
mA
mA
V
mV
µs
µA
µA
%
µs
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LC1111
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LINEAR INTEGRATED CIRCUIT
FUNCTION DESCRIPTION
Power-On-Reset (POR)
The UTC LC1111 monitors the VCC pin voltage (VCC) for power-on-reset function to prevent wrong operation.
The built-in POR circuit keeps the output shutting off until internal circuit is operating properly. Typical POR threshold
is 4.0V with 0.4V hysteresis.
Soft-Start
The UTC LC1111 provides an adjustable soft-start circuitry to control rise rate of the output voltage and limit the
current surge during start-up. The soft-start time is set with a capacitor from the SS pin to the ground. The capacitor
is charged to VP with a constant 4.5mA (typ.) current source.
Under-Voltage Protection (UVP)
The UTC LC1111 monitors the voltage on FB. When the voltage on FB falls below the under-voltage threshold,
the UVP circuit shuts off the output voltage immediately by pulling down DRV to 0V and latches UTC LC1111off,
requiring either a VCC POR or EN re-enable again to restart. The UTC LC1111 UVP is activated after VOUT voltage
has reached 90% POK threshold while the UTC LC1111 UVP is activated after VCC has been applied to VCC pin.
Enable Control
The UTC LC1111 has a dedicated enable pin (EN). A logic low signal applied to this pin shuts down the output.
Following a shutdown, a logic high signal re-enables the output through initiation of a new soft-start cycle. It’s not
necessary to use an external transistor to save cost.
Power-OK and Delay
The UTC LC1111 indicates the status of the output voltage by monitoring the feedback voltage (VFB) on FB pin.
As the VFB rises and reaches the rising Power-OK voltage threshold (VPOKTH), an internal delay function starts to
work. At the end of the delay time, the IC turns off the internal NMOS of the POK to indicate that the output is ok. As
the VFB falls and reaches the falling Power-OK voltage threshold, the IC turns on the NMOS of the POK (after a
debounce time of 5ms typical).
Output Voltage Regulation
The UTC LC1111 is a linear regulator controller. An external N-channel MOSFET should be connected to DRV
as the pass element. The output voltage set by the resistor divider is determined by:
R1
VOUT = 0.8 •(1+
)
R2
Where R1 is connected from VOUT to FB and R2 is connected from FB to GND.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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LC1111
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LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATION CIRCUIT
VCC
5V or 12V
CCC
1µF
SS
VCC
DRV
CSS
10nF
ON
OFF
CIN
47µF
R3
Optional
C1
Optional
UTC
LC1111
EN
VIN
1.5V
R1
10kΩ
FB
EN
GND
VOUT
1.2V/3A
COUT
100µF
R2
20kΩ
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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www.unisonic.com.tw
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