SEMTECH SC8863

SC8863
150mA Ultra Low Dropout,
Low Noise Regulator
POWER MANAGEMENT
Description
Features
The SC8863 is a low dropout linear regulator that
operates from a +2.5V to +6.0V input range and
delivers up to 150mA. A PMOS pass transistor allows
the low 110µA supply current to remain independent of
load, making these devices ideal for battery operated
portable equipment such as cellular phones, cordless
phones and personal digital assistants.
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Guaranteed 150mA output current
Works with ceramic capacitors
Fixed or adjustable output
Very small external components
Low 75µVRMS output noise
Very low supply current
Thermal overload protection
Reverse battery protection
Low power shutdown
Full industrial temperature range
Very low profile packaging available (1mm max.
height)
‹ Surface mount packaging (SOT-23-5 and
TSOT-23-5)
The SC8863 output voltage can be preset or adjusted
with an external resistor divider. Other features include
low power shutdown, short circuit protection, thermal
shutdown protection and reverse battery protection. The
SC8863 comes in the tiny 5 lead SOT-23 package (lead
free, fully WEEE and RoHS compliant available) and the
ultra low profile 5 lead TSOT-23.
Applications
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Typical Application Circuits
3
VIN > VOUT + VD(MAX)
1
U1
SC8863
IN
OUT
EN
C1
1uF Ceramic
SET
GND
Battery Powered Systems
Cellular Telephones
Cordless Telephones
Personal Digital Assistants
Portable Instrumentation
Modems
PCMCIA cards
4
VOUT @ IOUT up to 150mA
5
C2
1uF Ceramic
2
Internally Preset Output Voltage
3
VIN > VOUT + VD(MAX)
1
U1
SC8863
IN
OUT
EN
GND
SET
4
5
VOUT @ IOUT up to 150mA
R1
R1 

VOUT = 1.250 • 1 +

R
2

2
R2
10k
C1
1uF Ceramic
C2
2.2uF Ceramic
Externally Preset Output Voltage(1)
Note:
(1) Select R1 and R2 such that the current flowing through them is ≥ 10µA (i.e. R2 ≤ 120kΩ). A value of 10kΩ
is recommended for R2. Please see Component Selection - Externally Set Output on page 7.
Revision: November 8, 2005
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SC8863
POWER MANAGEMENT
Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified
in the Electrical Characteristics section is not implied.
Parameter
Symbol
Maximum
Units
EN, IN, OUT, SET to GND
VPIN
-0.3 to +7
V
Output Short Circuit Duration
tSC
Infinite
s
Thermal Resistance, Junction to Ambient
θJ A
256
°C/W
Thermal Resistance, Junction to Case
θJ C
81
°C/W
Operating Ambient Temperature Range
TA
-40 to +85
°C
Operating Junction Temperature Range
TJ
-40 to +150
°C
Storage Temperature Range
TSTG
-65 to +150
°C
Lead Temperature (Soldering) 10 sec
TLEAD
300
°C
Electrical Characteristics(1)
Unless specified: VIN = 3.6V, VSET = GND, VEN = VIN, TA = 25°C. Values in bold apply over full operating ambient temperature range.
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
6.0
V
130
µA
IN
Supply Voltage Range
VIN
Supply Current
IQ
2.5
IOUT = 0mA
100
160
50mA ≤ IOUT ≤ 150mA
110
160
µA
200
V E N = 0V
0.0001
1
µA
2
OUT
Output Voltage(2)
Line Regulation(2)
VOUT
REG(LINE)
IOUT = 1mA
-2.0%
1mA ≤ IOUT ≤ 150mA, VOUT + 1V ≤ VIN ≤ 5.5V
-3.5%
2.5V ≤ VIN ≤ 5.5V, VSET = VOUT, IOUT = 1mA
VOUT
+2.0%
V
+3.5%
5
10
mV
12
Load Regulation(2)
REG(LOAD)
IOUT = 0mA to 50mA
-10
-15
mV
-20
IOUT = 0mA to 100mA
-15
-20
mV
-25
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SC8863
POWER MANAGEMENT
Electrical Characteristics (Cont.)(1)
Unless specified: VIN = 3.6V, VSET = GND, VEN = VIN, TA = 25°C. Values in bold apply over full operating ambient temperature range.
Parameter
Symbol
Test Conditions
Load Regulation (Cont.)(2)
REG(LOAD)
IOUT = 0mA to 50mA, VSET = VOUT
Min
Typ
Max
Units
-2.5
-7.5
mV
-15.0
IOUT = 0mA to 100mA, VSET = VOUT
-5
-15
mV
-30
VD
Dropout Voltage(2)(3)
IOUT = 1mA
1.1
IOUT = 50mA
55
mV
90
mV
120
IOUT = 100mA
110
180
mV
240
Current Limit
ILIM
Output Voltage Noise
en
Power Supply Rejection
Ratio
PSRR
150
240
10Hz to 99kHz, IOUT = 50mA, COUT = 1µF
90
10Hz to 99kHz, IOUT = 50mA, COUT = 100µF
75
f ≤ 1kHz
55
350
mA
µVRMS
dB
EN
EN Input Threshold
1.8
VIH
V
0.4
VIL
EN Input Bias Current(4)
IEN
VEN = VIN
0
100
nA
200
SET
Sense/Select Threshold
VTH
SET Reference Voltage(2)
V SET
SET Input Leakage
ISET
20
55
80
mV
IOUT = 1mA
1.225
1.250
1.275
V
1mA ≤ IOUT ≤ 150mA, 2.5V ≤ VIN ≤ 5.5V
1.206
VSET = 1.3V
1.294
0.015
2.500
nA
5.000
Current(4)
Over Temperature Protection
High Trip Level
Hysteresis
THI
170
°C
THYST
10
°C
Notes:
(1) This device is ESD sensitive. Use of standard ESD handling precautions is required.
(2) Low duty cycle pulse testing with Kelvin connections required.
(3) Defined as the input to output differential at which the output voltage drops 100mV below the value measured
at a differential of 2V.
(4) Guaranteed by design.
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SC8863
POWER MANAGEMENT
Pin Configuration
Ordering Information
Top View
Part Number
P ackag e
SC8863-XXXCSKTR(1)(2)
SOT-23-5
SC8863-XXXCSKTRT(1)(2)(3)
SOT-23-5
SC8863-XXXTSKTR(1)(2)
TSOT-23-5
SC8863-XXXEVB(4)
N/A
Notes:
(1) Where -XXX denotes voltage options. Available
voltages are: 2.50V (-250), 2.80V (-280), 3.00V (-300),
and 3.30 (-330)V.
(2) Only available in tape and reel packaging. A reel
contains 3000 devices.
(3) Lead free product. Fully WEEE and RoHS compliant.
(4) Evaluation board for SC8863. Specify output voltage
option and packaging when ordering.
SOT-23-5 & TSOT-23-5
Block Diagram
Pin Descriptions
Pin
Pin Name Pin Function
1
EN
Active high enable pin. Connect to VIN if not being used.
2
GND
3
IN
4
OUT
Regulator output, sourcing up to 150mA.
5
SET
Connecting this pin to ground results in the internally preset value for VOUT. Connecting to an external
resistor divider changes VOUT to:
Ground pin. Can be used for heatsinking if needed.
Input pin.
R1 

VOUT = 1 .250 •  1 +

R2 

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SC8863
POWER MANAGEMENT
Typical Characteristics
2.86
Output Voltage vs. Junction Temperature
Output Current
vs. Output Current
2.86
VIN = 3.6V
TJ = 25°C
2.85
2.84
VIN = 3.6V
2.85
2.84
2.83
2.83
2.82
2.82
2.81
2.81
VOUT (V)
VOUT (V)
Output Voltage vs.
2.80
2.79
2.79
2.78
2.78
2.77
2.77
2.76
2.76
2.75
2.75
2.74
IO = 1mA
IO = 50mA
IO = 100mA
IO = 150mA
2.80
2.74
0
25
50
75
100
125
150
-50
-25
0
25
IOUT (mA)
1.275
Temperature vs. Output Current
1.290
1.270
1.260
1.255
VSET (V)
VSET (V)
VIN = 3.6V
1.280
1.250
1.245
IO = 1mA
IO = 50mA
IO = 100mA
IO = 150mA
1.250
1.240
1.240
1.230
1.235
1.220
1.230
1.225
1.210
0
25
50
75
100
125
150
-50
-25
0
IOUT (mA)
25
50
75
100
125
TJ (°C)
Dropout Voltage vs. Output Current
Line Regulation vs.
vs. Junction Temperature
Junction Temperature
12
SET = GND
10
200
REG(LINE) (mV)
175
VD (mV)
125
Output Current
1.260
225
100
SET Reference Voltage vs. Junction
1.265
250
75
SET Reference Voltage vs.
VIN = 3.6V
TJ = 25°C
1.270
50
TJ (°C)
150
-40°C
25°C
125°C
125
100
75
50
VIN = 2.5V to 5.5V
SET = OUT
IOUT = 1mA
8
6
4
2
25
0
0
0
25
50
75
100
125
150
-50
IOUT (mA)
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-25
0
25
50
75
100
125
TJ (°C)
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SC8863
POWER MANAGEMENT
Typical Characteristics (Cont.)
50
Load Regulation (VSET = GND)
Load Regulation (VSET = VOUT)
vs. Junction Temperature
vs. Junction Temperature
20.0
VIN = 3.6V
SET = GND
45
40
IOUT = 0mA to 150mA
IOUT = 0mA to 150mA
35
15.0
REG(LOAD) (mV)
REG(LOAD) (mV)
VIN = 3.6V
SET = OUT
17.5
30
25
20
IOUT = 0mA to 100mA
15
12.5
10.0
7.5
IOUT = 0mA to 100mA
5.0
10
2.5
IOUT = 0mA to 50mA
5
IOUT = 0mA to 50mA
0.0
0
-50
-25
0
25
50
75
100
-50
125
-25
0
25
TJ (°C)
50
75
100
125
75
100
125
TJ (°C)
Supply Current vs.
Supply Current vs.
Output Current
Junction Temperature
120
150
110
100
125
VIN = 3.6V
IOUT = 150mA
90
100
70
IQ (µA)
IQ (µA)
80
60
50
40
75
50
30
20
10
0
25
VIN = 3.6V
TJ = 25°C
0
0
25
50
75
100
125
-50
150
-25
0
25
IOUT (mA)
350
Current Limit vs.
Enable Input Threshold vs.
Junction Temperature
Junction Temperature
2.0
VIN = 3.6V
VIN = 3.6V
1.8
300
1.6
VIH, VIL (V)
250
ILIM (mA)
50
TJ (°C)
200
150
100
1.4
VIH
1.2
1.0
VIL
0.8
50
0.6
0
0.4
-50
-25
0
25
50
75
100
125
-50
TJ (°C)
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-25
0
25
50
75
100
125
TJ (°C)
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SC8863
POWER MANAGEMENT
Typical Characteristics (Cont.)
80
Sense/Select Threshold vs.
Output Spectral Noise Density
Junction Temperature
vs. Frequency
10
VIN = 3.6V
SC8863-2.8
VIN = 3.6V
IOUT = 50mA
TJ = 25°C
70
en (µV/√Hz)
VTH (mV)
60
50
1
COUT = 1µF
0.1
40
30
COUT = 100µF
0.01
20
-50
-25
0
25
50
75
100
0.1
125
1
10
100
f (kHz)
TJ (°C)
Applications Information
Theory Of Operation
output noise and improve the overall transient response.
The SC8863 is intended for applications where very low
dropout voltage, low supply current and low output noise
are critical. It provides a very simple, low cost solution
that uses very little pcb real estate. Fixed output voltage
options require the use of only two external capacitors
for operation.
Input capacitor: Semtech recommends the use of a 1µF
ceramic capacitor at the input. This allows for the device
being some distance from any bulk capacitance on the
rail. Additionally, input droop due to load transients is
reduced, improving load transient response.
Component Selection - Externally Set Output
Each voltage option has both fixed and adjustable
output voltage modes. Grounding the SET pin (pulling it
below the Sense/Select threshold of 55mV) will connect
the internal resistor divider to the error amplifier
resulting with the internally preset output voltage. If SET
is pulled above this threshold, then the Sense/Select
switch will connect the SET pin to the error amplifier. The
output will be regulated such that the voltage at SET will
equal VSET, the SET reference voltage (typically 1.250V).
Please refer to Figure 1 below. The output voltage can
be externally adjusted anywhere within the range from
1.25V to (VIN(MIN) - VD(MAX)). The output voltage will be in
accordance with the following equation:
R1 

VOUT = 1.250 • 1 +

 R2 
An active high enable pin (EN) is provided to allow the
customer to shut down the part and enter an extremely
low power Off-state. A logic Low signal will reduce the
supply current to 0.1nA.
U1
3
1
Component Selection - General
IN
EN
OUT
GND
SET
4
5
R1
2
C1
1uF Ceramic
Output capacitor: Semtech recommends a minimum
capacitance of 1µF at the output with an equivalent
series resistance (ESR) of <1Ω over temperature.
Ceramic capacitors are ideal for this application.
Increasing the bulk capacitance will further reduce
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SC8863
R2
10k
C2
2.2uF Ceramic
Figure 1: Externally set output
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SC8863
POWER MANAGEMENT
Applications Information (Cont.)
1% tolerance resistors are recommended. The values of
R1 and R2 should be selected such that the current flow
through them is ≥ 10µA (thus R2 ≤ 120kΩ). At high input
voltages and/or high output currents, stability may be
improved by increasing C2 to 2.2µF and reducing R2 to
10kΩ. See “Component Selection - General” for input
capacitor requirements.
With the standard SOT-23-5/TSOT-23-5 Land Pattern
shown at the end of this datasheet, and minimum trace
widths, the thermal impedance junction to ambient for
SC8863 is 256°C/W. Thus with no additional heatsinking,
TJ(MAX) = 135°C.
The junction temperature can be reduced further by the
use of larger trace widths, and connecting pcb copper
area to the GND pin (pin 2), which connectes directly to
the device substrate. Adding approximately one square
inch of pcb copper to pin 2 will reduce θ TH(J-A) to
approximately 130°C/W and TJ(MAX) to approximately
110°C, for example. Lower junction temperatures
improve overall output voltage accuracy. A sample pcb
layout for the Internally Preset Output Voltage circuit on
page 1 is shown in Figure 2 on page 9.
Thermal Considerations
The worst-case power dissipation for this part is given
by:
PD( MAX ) = (VIN(MAX ) − VOUT (MIN ) ) • IOUT (MAX ) + VIN( MAX ) • IQ(MAX )
For all practical purposes, it can be reduced to:
Layout Considerations
PD(MAX ) = (VIN( MAX ) − VOUT (MIN ) ) • IOUT (MAX )
While layout for linear devices is generally not as critical
as for a switching application, careful attention to detail
will ensure reliable operation. See Figure 2 on page 9 for
a sample layout.
Looking at a typical application:
VIN(MAX) = 4.2V
VOUT = (3 - 3.5%) = 2.895V worst-case
IOUT = 150mA
TA = 85°C
1) Attaching the part to a larger copper footprint will
enable better heat transfer from the device, especially
on PCBs where there are internal ground and power
planes.
This gives us:
2) Place the input and output capacitors close to the
device for optimal transient response and device
behavior.
PD( MAX ) = (4.2 − 2.895 ) • 0.150 = 196mW
Using this figure, we can calculate the maximum thermal
impedance allowable to maintain TJ ≤ 150°C:
θ( J− A )(MAX ) =
(T
J(MAX )
− TA (MAX ) )
PD(MAX )
 2005 Semtech Corp.
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3) Connect all ground connections directly to the ground
plane. If there is no ground plane, connect to a common
local ground point before connecting to board ground.
(150 − 85) = 332°C / W
0.196
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SC8863
POWER MANAGEMENT
Applications Information (Cont.)
Top Silk Screen
Top Copper
Figure 2: Suggested pcb layout based upon internally preset output voltage application on page 1.
Notes:
(1) All vias go to the ground plane.
(2) Copper area on pin 2 is recommended, but not required. Connect to the ground plane with a via or vias.
Marking Information
Top Mark
Bottom Mark
8XXX
yyww
8 = 8863 in SOT-23-5
XXX = voltage option
(examples: 8280 = SC8863-280CSK)
yyww = Date code
(example: 0108 for week 8 of 2001)
Top Mark
Bottom Mark
T8XX
yyww
T8 = 8863 in TSOT-23-5
XX = voltage option
(examples: T828 = SC8863-280TSK)
yyww = Date code
(example: 0108 for week 8 of 2001)
SOT-23-5
TSOT-23-5
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SC8863
POWER MANAGEMENT
Outline Drawing - SOT-23-5
Outline Drawing - TSOT-23-5
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SC8863
POWER MANAGEMENT
Land Pattern - SOT-23-5 & TSOT-23-5
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
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