Datasheet SC8863-2.50CSKTR, SC8863-2.80CSKTR, SC8863-3.00CSKTR, SC8863-3.30CSKTR Datasheet (Semtech Corporation)
Page 1
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
1
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) Add suffix ‘TR’ for tape and reel.
DESCRIPTION
The SC8863 is a low dropout linear regulator that
operates from a +2.5V to +5.5V 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.
The SC8863 output voltage can be preset or adjusted
with an external resistor divider. Other features include
low powered shutdown, short circuit protection, thermal
shutdown protection and reverse battery protection.
The SC8863 comes in the tiny 5 lead SOT-23
package.
FEATURES
•
Guaranteed 150 mA output current
•
Fixed or adjustable output
•
Very small external components
•
Low 75µV
RMS
output noise
•
Very low supply current
•
Thermal overload protection
•
Reverse battery protection
•
Low power shutdown
•
Surface mount packaging (5 pin SOT-23)
•
Full industrial temperature range
•
Battery Powered Systems
•
Cellular Telephones
•
Cordless Telephones
•
Personal Digital Assistants
•
Portable Instrumentation
•
Modems
•
PCMCIA cards
PIN CONFIGURATION
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
Part Number Package
SC8863-XXXCSK
(1)(2)
SOT-23-5
ORDERING INFORMATION
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
APPLICATIONS
Parameter Symbol Maximum Units
Input Supply Voltage V
IN
-0.6 to +7 V
Power Dissipation
T
A
= 70°C
P
D
571 mW
Thermal Resistance
θ
JA
256 °C/W
θ
JC
81 °C/W
Operating Ambient
Temperature Range
T
A
-40 to +85 °C
Operating Junction
Temperature Range
T
J
-40 to +150 °C
Storage Temperature
Range
T
STG
-65 to +150 °C
Lead Temperature
(Soldering) 10 Sec
T
LEAD
+300 °C
ESD Rating ESD 1.25 kV
Page 2
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
2
PIN DESCRIPTIONS
Pin # Pin Name Description
1 EN Active high enable pin. Connect to VIN if not being used.
2 GND Ground pin. Can be used for heatsinking if needed.
3 IN Input pin.
4 OUT Regulator output, sourcing up to 150mA
5 SET Connecting this pin to ground results in the internally preset value for
V
OUT
. Connecting to an external resistor divider changes V
OUT
to:
TYPICAL APPLICATION - EXTERNALLY SET OUTPUT VOLTAGE
(1)
TYPICAL APPLICATION - INTERNALLY PRESET OUTPUT VOLTAGE
VIN > VOUT + VD(MAX)
VOUT @ IOUT up to 150mA
U1 SC8863
1
2
3 4
5
EN
GND
VIN VO
SET
C1
1uF Ceramic
C2
1uF Ceramic
+•=
2R
1R
1250.1V
OUT
NOTES:
(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.
VOUT @ IOUT up to 150mA
VIN > VOUT + VD(MAX)
C2
2.2uF Ceramic
U1 SC8863
1
2
3 4
5
EN
GND
VIN VO
SET
R1
R2
10kC1
1uF Ceramic
Page 3
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
3
ELECTRICAL CHARACTERISTICS
Unless specified: VIN = 3.6V, V
SET
= GND, VEN = VIN, TA = 25°C. Values in
bold
apply over full operating ambient temperature range.
Parameter Symbol Conditions Min Typ Max Units
IN
Supply Voltage Range V
IN
2.5 5.5
V
Supply Current I
Q
I
OUT
= 0mA 100 130 µA
160
50mA ≤ I
OUT
≤ 150mA
110 160 µA
200
V
EN
= 0V 0.0001 1 µA
2
OUT
Output Voltage
(1)
V
OUT
I
OUT
= 1mA -2.0% V
OUT
+2.0% V
1mA ≤ I
OUT
≤ 150mA, V
OUT
+1V ≤ VIN ≤ 5.5V
-3.5% +3.5%
Line Regulation
(1)
REG
(LINE)
2.5V ≤ VIN ≤ 5.5V, SET = OUT, I
OUT
= 1mA
510mV
12
Load Regulation
(1)
REG
(LOAD)
I
OUT
= 0mA to 50mA -10 -15 mV
-20
I
OUT
= 0mA to 100mA -15 -20 mV
-25
I
OUT
= 0mA to 50mA, SET = OUT -2.5 -7.5 mV
-15.0
I
OUT
= 0mA to 100mA, SET = OUT -5 -15 mV
-30
Dropout Voltage
(1)(2)
V
D
I
OUT
= 1mA 1.1 mV
I
OUT
= 50mA 55 90 mV
120
I
OUT
= 100mA 110 180 mV
240
Current Limit I
LIM
150
240
350
mA
Output Voltage Noise e
n
10Hz to 99kHz, I
OUT
= 50mA, C
OUT
= 1µF 90 µV
RMS
C
OUT
= 100µF 75
Power Supply Rejection
Ratio
PSRR
f ≤ 1kHz
55 dB
Page 4
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
4
ELECTRICAL CHARACTERISTICS (Cont.)
Unless specified: VIN = 3.6V, V
SET
= GND, VEN = VIN, TA = 25°C. Values in
bold
apply over full operating ambient temperature range.
Parameter Symbol Conditions Min Typ Max Units
EN
EN Input Threshold V
IH
1.8
V
V
IL
0.4
EN Input Bias Current
(3)
I
EN
EN = V
IN
0 100 nA
200
SET
Sense/Select Threshold V
TH
20
55
80
mV
SET Reference Voltage
(1)
V
SET
I
OUT
= 1mA 1.225 1.250 1.275 V
1mA
≤
I
OUT
≤ 150mA, 2.5V ≤ VIN ≤ 5.5V
1.206 1.294
SET Input Leakage Current
(3)
I
SET
SET = 1.3V 0.015 2.500 nA
5.000
OVER TEMPERATURE PROTECTION
High Trip Level T
HI
170 °C
Hysteresis T
HYST
10 °C
NOTE:
(1) Low duty cycle pulse resting with Kelvin corrections required.
(2) Defined as the input to output differential at which the output voltage drops 100mV below the value measured at
a differential of 2V.
(3) Guaranteed by design.
Page 5
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
5
TYPICAL CHARACTERISTICS
2.74
2.75
2.76
2.77
2.78
2.79
2.80
2.81
2.82
2.83
2.84
2.85
2.86
0 255075100125150
I
OUT
(mA)
V
OUT
(V)
VIN = 3.6V
T
J
= 25°C
Output Voltage vs. Output Current
2.74
2.75
2.76
2.77
2.78
2.79
2.80
2.81
2.82
2.83
2.84
2.85
2.86
-50-250 255075100125
T
J
(°C)
V
OUT
(V)
IO = 1mA
IO = 50mA
IO = 100mA
IO = 150mA
VIN = 3.6V
Output Voltage vs. Junction
Temperature vs. Output Current
1.210
1.220
1.230
1.240
1.250
1.260
1.270
1.280
1.290
-50-250 255075100125
T
J
(°C)
V
SET
(V)
IO = 1mA
IO = 50mA
IO = 100mA
IO = 150mA
VIN = 3.6V
SET Reference Voltage vs. Junction
Temperature vs. Output Current
1.225
1.230
1.235
1.240
1.245
1.250
1.255
1.260
1.265
1.270
1.275
0 255075100125150
I
OUT
(mA)
V
SET
(V)
VIN = 3.6V
T
J
= 25°C
SET Reference Voltage vs.
Output Current
0
2
4
6
8
10
12
-50-250 255075100125
T
J
(°C)
REG
(LINE)
(mV)
VIN = 2.5V to 5.5V
SET = OUT
I
OUT
= 1mA
Line Regulation vs.
Junction Temperature
0
25
50
75
100
125
150
175
200
225
250
0 255075100125150
I
OUT
(mA)
V
D
(mV)
-40°C
25°C
125°C
SET = GND
Dropout Voltage vs. Output Current
vs. Junction Temperature
Page 6
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
6
TYPICAL CHARACTERISTICS (Cont.)
0
5
10
15
20
25
30
35
40
45
50
-50-250 255075100125
T
J
(°C)
REG
(LOAD)
(mV)
VIN = 3.6V
SET = GND
I
OUT
= 0mA to 50mA
I
OUT
= 0mA to 100mA
I
OUT
= 0mA to 150mA
Load Regulation (SET = GND)
vs. Junction Temperature
0.0
2.5
5.0
7.5
10.0
12.5
15.0
17.5
20.0
-50 -25 0 25 50 75 100 125
T
J
(°C)
REG
(LOAD)
(mV)
VIN = 3.6V
SET = OUT
I
OUT
= 0mA to 150mA
I
OUT
= 0mA to 100mA
I
OUT
= 0mA to 50mA
Load Regulation (SET = OUT)
vs. Junction Temperature
0
25
50
75
100
125
150
-50 -25 0 25 50 75 100 125
T
J
(°C)
I
Q
(µA)
VIN = 3.6V
I
OUT
= 150mA
Supply Current vs.
Junction Temperature
0
10
20
30
40
50
60
70
80
90
100
110
120
0 25 50 75 100 125 150
I
OUT
(mA)
I
Q
(µA)
VIN = 3.6V
T
J
= 25°C
Supply Current
vs. Output Current
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
-50 -25 0 25 50 75 100 125
T
J
(°C)
V
IH
, V
IL
(V)
VIN = 3.6V
V
IH
V
IL
Enable Input Threshold vs.
Junction Temperature
0
50
100
150
200
250
300
350
-50 -25 0 25 50 75 100 125
T
J
(°C)
I
LIM
(mA)
VIN = 3.6V
Current Limit vs.
Junction Temperature
Page 7
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
7
TYPICAL CHARACTERISTICS (Cont.)
20
30
40
50
60
70
80
-50-250 255075100125
T
J
(°C)
V
TH
(mV)
VIN = 3.6V
Sense/Select Threshold
vs. Junction Temperature
0.01
0.1
1
10
0.1 1 10 100
f (kHz)
e
n
(µV/
√
√√
√
Hz)
SC8863-2.8
VIN = 3.6V
I
OUT
= 50mA
T
J
= 25°C
C
OUT
= 1µF
C
OUT
= 100µF
Output Spectral Noise Density
vs. Frequency
APPLICATIONS INFORMATION
Theory Of Operation
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.
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 V
SET
, the SET reference voltage
(typically 1.250V).
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.
Component Selection - General
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. Increas-
ing the bulk capacitance will further reduce output
noise and improve the overall transient response.
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
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:
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, sta-
C2
2.2uF Ceramic
U1 SC8863
1
2
3 4
5
EN
GND
VIN VO
SET
R1
R2
10k
C1
1uF Ceramic
Figure 1: Externally set output
+•=
2R
1R
1250.1VO
Page 8
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
8
bility may be improved by increasing C2 to 2.2µF and
reducing R2 to 10kΩ. See “Component Selection General” for input capacitor requirements.
Thermal Considerations
The worst-case power dissipation for this part is given
by:
For all practical purposes, it can be reduced to:
Looking at a typical application:
VIN
(MAX)
= 4.2V
VO = 3V - 3.5% worst-case
I
O
= 150mA
T
A
= 85°C
Using this figure, we can calculate the maximum thermal impedance allowable to maintain T
J
≤ 150°C:
With the standard SOT-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,
T
J(MAX)
= 135°C.
The junction temperature can be further reduced 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 T
J(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 2 is shown in Figure 2 below.
Layout Considerations
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 below
for a sample layout.
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.
2) Place the input and output capacitors (and the capacitor from OUT to SET for adjustable applications)
close to the device for optimal transient response and
device behaviour.
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.
()
()
W/C332
196.0
85150
P
TT
)MAX(D
)MAX(A)MAX(J
)MAX)(AJ(
°=
−
=
−
=θ
−
() ()
()
)MAX(Q)MAX()MAX(OMINMAX)MAX(D
IVINIVOVINP
•+•−=
() ()
()
)MAX(OMINMAX)MAX(D
IVOVINP
•−=
()
mW196150.0895.22.4P
)MAX(D
=•−=
Top Copper Top Silk Screen
Figure 2: Suggested pcb layout based upon internally preset output voltage application on page 2.
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.
Page 9
150mA ULTRA LOW DROPOUT,
LOW NOISE REGULATOR
© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320
SC8863
March 1, 2000
9
DEVICE OUTLINE - SOT23-5
LAND PATTERN - SOT23-5
ECN 00-915
Loading...