How it Works
Datasheet
Loading...
SPX2920M3

Datasheet SPX2920M3, SPX2920M3-2.5, SPX2920M3-3.3, SPX2920M3-5.0, SPX2920S Datasheet (Sipex Corporation)

...
Download
Page 1
SPX2920
400mA Low Drop Out Voltage Regulator
(PRELIMINARY INFORMATION)
FEATURES
Output Accuracy 2.5V, 3.3V, 5.0V, @ 400mA Output • Battery Powered Systems
•
Very Low Quiescent Current
•
Low Dropout Voltage
•
Extremely Tight Load And Line Regulation
•
Very Low Temperature Coefficient
•
Current & Thermal Limiting
•
Error Flag Warns Of Output Dropout
•
Logic-Controlled Electronic Shutdown
•
Output Programmable From 1.24V to 26V
•
PRODUCT DESCRIPTION
The SPX2920 is a low power voltage regulator. This device is an excellent choice for use in battery-powered applications such as cordless telephones, radio control systems, and portable computers. The SPX2920 features very low quiescent current (140µA Typ.) and very low dropout voltage. This includes a tight initial tolerance of 1% max and very low output temperature coefficient, making the SPX2920 useful as a low-power voltage reference.
The error flag output feature is used as power-on reset for warning of a low output voltage, due to a falling voltage input of batteries. Another feature is the logic-compatible shutdown input which enables the regulator to be switched on and off. The SPX2920 is offered in 3-pin and 5-pin TO-220 package, SO-8 (same pin out as SPX2951), SOT-223, and surface mount TO-263 packages.
The regulator output voltage (of the 8-pin SO-8 and 5-pin TO-220 & TO-263) may be pin-strapped for a 2.5V, 3.3V and 5.0V or programmed from 1.24V to 26V with an external pair of resistors..
PIN CONNECTIONS
APPLICATIONS
Cordless Telephones
•
Radio Control Systems
•
Portable/Palm Top/Notebook Computers
•
Portable Consumer Equipment
•
Portable Instrumentation
•
Automotive Electronics
•
SMPS Post-Regulator
•
Voltage Reference
•
TO-263-5 Package
SPX2920
1
45
23
Top View
Five Lead Package Pin Functions:
SPX2920U51 SPX2920U52
SPX2920T51
1)
ERROR
2)
V
IN
3)
GND
4)
V
OUT
5)
SHUTDOWN
SPX2920T52
ADJ
SHUTDOWN
GND
V
IN
V
OUT
TO-220-5 Package
SPX2920
54321
Front View
TO-263-3 Package
V
SPX2920
1
GND
IN
Top View
TO-220-3 Package
SPX2920
V
GND
IN
Front View
321
V
OUT
3
2
V
OUT
SOT-223 (M3)Package
SPX2920
132
GND
V
IN
Top View
V
SHUTDOWN
OUT
8-Pin Surface Mount
V
1
OUT
2
SPX2920
3
GND
4
Top View
8
7
6
5
V
IN
FEEDBACKSENSE
5V/ 3.3V TAP
ERROR
Rev. 10/30/00
Page 2
SPX2920
ABSOLUTE MAXIMUM RATINGS
Power Dissipation..........................................Internally Limited Input Supply Voltage .....................................+3.0V to +60V
Lead Temp. (Soldering, 5 Seconds) ................................ 260°C Feedback Input Voltage ..................................-1.5V to +30V
Storage Temperature Range .............................. -65° to +150°C Shutdown Input Voltage..................................-0.3V to +30V
Operating Junction Temperature Range (Note 9) Error Comparator Output................................-0.3V to +30V
SPX2920................................................ -40C° to +125°C ESD Rating ............................................................2KV Min
ESD Rating ................................................................ 2KV Min
ELECTRICAL CHARACTERISTICS
full operating temperature range.
PARAMETER
2.5V Version
Output Voltage
3.3V Version
Output Voltage
5V Version
Output Voltage
All Voltage Options
Output Voltage Temperature Coefficient Line Regulation ( Note 3)
Load Regulation ( Note 3 ) IL = 1 to 400mA
Dropout Voltage ( Note 5 )
Ground Current I
Current Limit
Thermal Regulation 0.05 0.2 %/w
Output Noise, 10Hz to 100kHz I
= 100mA
L
Adjustable Versions only
Reference Voltage
Reference Voltage Over Temperature (Note 6)
Feedback Pin Bias Current
Reference Voltage Temperature Coefficient Feedback Pin Bias Current Temperature Coefficient
1mA ≤I
1mA ≤I
1mA ≤I
(Note 1) 6V ≤ V
I
= 0.1 to 1mA
L
I
= 1mA
L
I
= 400mA
L
= 1mA
L
I
= 100mA
L
I
= 250mA
L
I
= 400mA
L
V
OUT
C
L
C
L
(Note 7)
at V
IN =VOUT
CONDITIONS
(Note 2)
400mA
≤
L
400mA
≤
L
400mA
≤
L
±15V,TA=25°C, unless otherwise specified.
Typ.
2.5
2.5
3.3
3.3
5.0
5.0
Boldface
SPX2920
Min Max
2.475
2.450
3.267
3.234
4.950
4.9
2.525
2.550
3.333
3.366
5.050
20
≤30V (Note 4)
IN
0.03 0.1
0.04 0.20
60
100
375
140
200
1.3
5
13
= 0 1000
= 10µF = 100µF
400 260
Typ SPX2920
1.235 1.223
1.210
1.185 1.285 V
20 40
50 ppm/°C
0.1 nA/°C
applies over the
5.10
100
0.40
0.30
150
400
500
300
2
2.5
9
12
15
25
1200
1.247
1.260
60
UNITS
ppm/°C
%max
%max
V Vrms
µ
V
V
V
mV
A
µ
mA
mA
mA
mA
V
nA
Rev. 10/30/00
Page 3
A
(Continued)
Error Comparator
Output Leakage Current V
Output Low Voltage VIN = 4.5V
PARAMETER
CONDITIONS
(Note 2)
= 30V 0.01 1.00
0H
Typ. SPX2920
Min Max
2.00
150 250
I0L = 400µA
400
Upper Threshold Voltage (Note 8) 60 40
25
Lower Threshold Voltage (Note 8) 75 95
140
SPX2920
UNITS
µ
mV
mV
mV
Hysteresis (Note 8) 15 mV
Shutdown Input
Input logic Voltage
Shut down Pin Input Current VS = 2.4V
Regulator Output Current in Shutdown 3 10
Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.
Note 1:
Unless otherwise specified all limits are guaranteed for T
Note 2:
feedback tied to 5V tap and output tied to output sense (V
Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are
Note 3:
covered under the specification for thermal regulation.
: Line regulation for the SPX2920 is tested at 150°C for I
Note 4
typical performance characteristics for line regulation versus temperature and load current.
Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below its nominal value measured at 1V differential at
Note 5:
very low values of programmed output voltage, the minimum input supply voltage of 2V ( 2.3V over temperature) must be taken into account.
V
Note 6: Note 7:
express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V voltage of 5V, the Error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant as a percent of V V
Note 8: Note 9:
The thermal resistance of the 8-Pin DIP package is 105°C/W junction-to-ambient when soldered directly to a PC board. Junction-to-ambient thermal resistance for the SOIC (S) package is 160°C/W.
REF
Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at 6V input. To
is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed.
OUT
V
SHUTDOWN
The junction -to-ambient thermal resistance of the TO-92 package is 180°C/ W with 0.4” leads and 160°C/ W with 0.25” leads to a PC board.
≤ (Vin - 1V), 2.3 ≤Vin≤30V, 100µA≤I
V
≤
OUT
≥ 2V, VIN ≤ 30V, V
=0, Feedback pin tied to 5V Tap.
OUT
UNREGULATED DC
+
1.3 Low (Regulator ON)
High (Regulator OFF)
V
= 26V
S
30
450
2.0
50
0.7
100
600
750
20
= 25°C, VIN = 6V, IL = 100µA and CL = 1µF. Additional conditions for the 8-pin versions are
j
= 5V) and V
OUT
≤
L
L
250 mA, T
SHUTDOWN
= 1 mA. For IL = 100µA and TJ = 125°C, line regulation is guaranteed by design to 0.2%. See
T
≤
J
JMAX
≤ 0.8V.
.
= (R1 + R2)/R2. For example, at a programmed output
OUT/VREF
V
µ
µ
OUT
A
A
as
7
8
1
5V @ 500mA
MAX
2
FROM TTL
180k
..
Ω
+ _
ERROR
3
+
+
60 mV
+
_
1.23V
REFERENCE
AMPLIFIER
ERROR DETECTION COMPARATOR
SPX2920 Block Diagram
6
Ω
..
330k
+
60k
..
Ω
5
4
1 uF
TO CMOS OR TTL
Rev. 10/30/00
Page 4
APPLICATION HINTS
EXTERNAL CAPACITORS
The stability of the SPX2920 requires a 2.2µF or greater capacitor between output and ground. Oscillation could occur without this capacitor. Most types of tantalum or aluminum electrolytic works fine here. For operations of below -25°C solid tantalum is recommended since the many aluminum types have electrolytes the freeze at about -30°C. The ESR of about 5Ω or less and resonant frequency above 500kHz are the most important parameters in the value of the capacitor. The capacitor value can be increased without limit. At lower values of output current, less output capacitance is required for stability. For the currents below 10mA the value of the capacitor can be reduced to 0.5µF and 0.15µF for 1mA. More output capacitance needed for the 8-pin version at voltages below 5V since it runs the error amplifier at lower gain. At worst case 5µF or greater must be used for the condition of 250mA load at
1.23V output. The SPX2920, unlike other low dropout regulators will remain stable and in regulation with no load in addition to the internal voltage divider. This feature is especially important in application like CMOS RAM keep-alive. When setting the output voltage of the SPX2920, a minimum load of 10mA is recommended. If there is more than 10 inches of wire between the input and the AC filter capacitor or if a battery is used as the input then a 0.1µF tantalum or aluminum electrolytic capacitor should be placed from the input to the ground. Instability can occur if there is stray capacitance to the SPX2920 feedback terminal (pin 7). This could cause more problems when using a higher value of external resistors to set the output voltage.
VOLTAGE 1.3V
OUTPUT
VOLTAGE
_______
ERROR*
INP UT
* See App lication Info.
4.75V
+
5.0V
+
Figure 1. ERRO R Output Timing
+
+
_______
ON
SPX2920
This problem can be fixed by adding a 100pF capacitor between output and feedback and increasing the output capacitor to at least
3.3µF.
ERROR DETECTION COMPARATOR OUTPUT
The Comparator produces a logic low output whenever the SPX2920 output falls out of regulation by more than around 5%. This is around 60mV offset divided by the 1.235 reference voltage. This trip level remains 5% below normal regardless of the programmed output voltage of the regulator. Figure 1 shows the timing diagram depicting the ERROR signal and the regulator output voltage as the SPX2920 input is ramped up and down. The ERROR signal becomes low at around 1.3V input, and goes high around 5V input (input voltage at which Vout = 4.75). Since the SPX2920’s dropout voltage is load dependent, the input voltage trip point (around 5V) will vary with the load current. The output voltage trip point (approx. 4.75V) does not vary with load. The error comparator has an open-collector output, which requires an external pull-up resistor. Depending on the system requirements the resistor may be returned to 5V output or other supply voltage. In determining the value of this resistor, note that the output is rated to sink 400µA, this value adds to battery drain in a low battery condition. Suggested values range from 100K to 1MΩ. If the output is unused this resistor is not required.
PROGRAMMING THE OUTPUT VOLTAGE OF SPX2920
The SPX2920 may be pin-strapped for 5V using its internal voltage divider by tying Pin 1 (output) to Pin 2 (sense) and Pin 7 (feedback) to Pin 6 (5V Tap).
+V
IN
Shutdown Input
100k
OFF
8
+V
IN
SPX2920
3
SD
GND
ERROR
4
1
V
OUT
R
1
V
R
2
FB
7
5
0.01uF
REF
1.2V TO 26V
+
10uF
ERROR
OUTPUT
Rev. 10/30/00
Page 5
Also, it may be programmed for any output voltage between its
1.235V reference and its 30V maximum rating. As seen in Figure 2, an external pair of resistors is required. Refer to the below equation for the programming of the output voltage::
V
OUT
= V
× ( 1 + R1/ R2 )+ IFBR
REF
1
The V
is 1.235 and IFB is the feedback bias current, nominally
REF
-20nA. The minimum recommended load current of 1 µA forces an upper limit of 1.2 MΩ on value of R2. If no load is presented the I
produces an error of typically 2% in V
FB
eliminated at room temperature by trimming R
, which may be
OUT
. To improve the
1
accuracy choose the value of R2 = 100k this reduces the error by
0.17% and increases the resistor program current by 12µA. Since the SPX2920 typically draws 60 µA at no load with Pin 2 open­circuited this is a small price to pay
(max):
+
θ
θ
(max)
junction to case,
θ
(J-C)
+
θ
(C-H)
G
(max). TJ (max)
R
(max) maximum
A
can be calculated
(j-A)
(H-A)
θ
(C-H)
HEAT SINK REQUIREMENTS
Depending on the maximum ambient temperature and maximum power dissipation a heat sink may be required with the SPX2920. The junction temperature range has to be within the range specified under Absolute Maximum Ratings under all possible operating conditions. To find out if a heat sink is required, the maximum power dissipation of the device needs to be calculated. This is the maximum specific AC voltage that must be taken into consideration at input. Figure 3 shows the condition and power dissipation which should be calculated with the following formula:
P
= (VIN - 5) IL + (VIN)I
TOTAL
Next step is to calculate the temperature rise T maximum allowable junction temperature, T ambient temperature :
T
(max) = TJ (max) - TA (max)
R
Junction to ambient thermal resistance after determining of P
If the
is 60°C/W or higher, the device could be operated
θ
(J-A)
without a heat sink. If the value is below 60°C/W then the heat sink is required and the thermal resistance of the heat sink can be calculated by the following formula, case to heat sink,
TOTAL & TR
= TR (max)/P
θ
(J-A)
heat sink to ambient:
θ
(H-A)
=
θ
θ
(J-A)
(J-C)
SPX2920
REDUCING OUTPUT NOISE
It may be an advantage to reduce the AC noise present at the output. One way is to reduce the regulator bandwidth by increasing the size of the output capacitor. This is the only way that noise can be reduced on the 3 lead SPX2920 but is relatively inefficient, as increasing the capacitor from 1µF to 220µF only decreases the noise from 430µV to 160µV Vrms for a 100kHz bandwidth at 5V output. Noise could also be reduced fourfold by a bypass capacitor across R
,
1
since it reduces the high frequency gain from 4 to unity. Pick
C
BYPASS
1 / 2πR
≅
× 200 Hz
1
or choose 0.01µF. When doing this, the output capacitor must be increased to 3.3µF to maintain stability. These changes reduce the output noise from 430µV to 100µV Vrms for a 100kHz bandwidth at 5V output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages.
I
VIN
IIN = IL + IG
IN
IN
SPX2920
GND
I
OUT
G
Figure 3. 5V Regulator Circuit
5V
+
2.2 uF
IL
LOAD
Rev. 10/30/00
Page 6
TYPICAL APPLICATIONS
+V
IN
SHUTDOWN
INPUT
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 4mV TO 400mV. DEPENDING ON LOAD CURRENT.
8
+V
IN
SPX2920
3
SD
GND
4
V
ERROR
FB
7
OUT
1
5
Wide Input Voltage Range Current Limit.
*V
OUT
ERROR
OUTPUT
= V
SPX2920
IN
Rev. 10/30/00
Page 7
SPX2920
ORDERING INFORMATION
Ordering No. Output Voltage Packages
SPX2920U3 SPX2920U3-2.5 SPX2920U3-3.3 SPX2920U3-5.0 SPX2920U5 SPX2920U5-2.5 SPX2920U5-3.3 SPX2920U5-5.0 SPX2920T3 SPX2920T3-2.5 SPX2920T3-3.3 SPX2920T3-5.0 SPX2920T5 SPX2920T5-2.5 SPX2920T5-3.3 SPX2920T5-5.0 SPX2920M3 SPX2920M3-2.5 SPX2920M3-3.3 SPX2920M3-5.0 SPX2920S SPX2920S-2.5 SPX2920S-3.3 SPX2920S-5.0
Adj 3 Lead TO-220
2.5V 3 Lead TO-220
3.3V 3 Lead TO-220
5.0V 3 Lead TO-220 Adj 5 Lead TO-220
2.5V 5 Lead TO-220
3.3V 5 Lead TO-220
5.0V 5 Lead TO-220 Adj 3 Lead TO-263
2.5V 3 Lead TO-263
3.3V 3 Lead TO-263
5.0V 3 Lead TO-263 Adj 5 Lead TO-263
2.5V 5 Lead TO-263
3.3V 5 Lead TO-263
5.0V 5 Lead TO-263 Adj 3 Lead TO-223
2.5V 3 Lead TO-223
3.3V 3 Lead TO-223
5.0V 3 Lead TO-223 Adj 8 Lead SOIC
2.5V 8 Lead SOIC
3.3V 8 Lead SOIC
5.0V 8 Lead SOIC
SIGNAL PROCESSING EXCELLENCE
Corporation
Sipex Corporation
Headquarters and Main Offices:
22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: sales@sipex.com
233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 935-7600 FAX: (408) 934-7500
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.
Rev. 10/30/00
Loading...
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use