a
FEATURES Operates From 2.0 V to 30 V Input Voltages Only 110 A Supply Current (Typical) Step-Up or Step-Down Mode Operation Very Few External Components Required Low Battery Detector On-Chip User-Adjustable Current Limit Internal 1 A Power Switch Fixed or Adjustable Output Voltage Versions 8-Pin DIP or SO-8 Package APPLICATIONS Notebook and Palmtop Computers Cellular Telephones Flash Memory Vpp Generators 3 V to 5 V, 5 V to 12 V Converters 9 V to 5 V, 12 V to 5 V Converters Portable Instruments LCD Bias Generators
VIN
Micropower DC-DC Converter ADP1173
FUNCTIONAL BLOCK DIAGRAMS
SET
ADP1173
A2 VIN GAIN BLOCK/ ERROR AMP 1.245V REFERENCE AO ILIM SW1 A1 OSCILLATOR DRIVER SW2
COMPARATOR GND FB
SET
ADP1173-3.3 ADP1173-5 ADP1173-12
A2 GAIN BLOCK/ ERROR AMP 1.245V REFERENCE AO ILIM SW1 A1 OSCILLATOR DRIVER ADP1173-3.3: R1 = 456kΩ ADP1173-5: R1 = 250kΩ ADP1173-12: R1 = 87.4kΩ SENSE SW2
GENERAL DESCRIPTION
The ADP1173 is part of a family of step-up/step-down switching regulators that operates from an input supply voltage of as little as 2 V to 12 V in step-up mode and to 30 V in step-down mode. The ADP1173 consumes as little as 110 µA in standby mode, making it ideal for applications that need low quiescent current. An auxiliary gain amplifier can serve as a low battery detector, linear regulator (under voltage lockout) or error amplifier. The ADP1173 can deliver 80 mA at 5 V from a 3 V input in step-up configuration or 100 mA at 5 V from a 12 V input in step-down configuration. For input voltages of less than 2 V use the ADP1073.
R1
COMPARATOR R2 753kΩ
GND
R EV. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 World Wide Web Site: http://www.analog.com Fax: 617/326-8703 © Analog Devices, Inc., 1997
ADP1173–SPECIFICATIONS (@ T = 0 C to +70 C, V
A
IN
= 3 V unless otherwise noted)
Min Typ 110 135 135 250 2.0 1.20 3.14 4.75 11.4 1.245 3.30 5.00 12.0 5 13 20 50 16 24 55 23 60 70 0.15 0.2 0.02 0.5 0.8 12.6 30 1.30 3.46 5.25 12.6 12 35 55 100 32 63 32 290 150 0.4 0.4 0.075 0.85 1.0 1.4 1.5 1.7 Max 150 Units µA µA µA µA V V V V V V mV mV mV mV kHz % µs nA nA V %/V %/V V V V V V V/V mA
Model QUIESCENT CURRENT
Symbol IQ
Conditions Switch Off No Load, TA = +25°C ADP1173-3.3 ADP1173-5 ADP1173-12 Step-Up Mode Step-Down Mode ADP11731
QUIESCENT CURRENT, BOOST MODE IQ CONFIGURATION
INPUT VOLTAGE COMPARATOR TRIP POINT VOLTAGE OUTPUT SENSE VOLTAGE
VIN
VOUT
ADP1173-3.32 ADP1173-52 ADP1173-122 ADP1173 ADP1173-3.3 ADP1173-5 ADP1173-12
COMPARATOR HYSTERESIS OUTPUT HYSTERESIS
OSCILLATOR FREQUENCY DUTY CYCLE SWITCH ON TIME FEEDBACK PIN BIAS CURRENT SET PIN BIAS CURRENT GAIN BLOCK OUTPUT LOW REFERENCE LINE REGULATION SWSAT VOLTAGE, STEP-UP MODE
fOSC Full Load tON ILIM Tied to VIN ADP1173, VFB = 0 V VSET = VREF VOL ISINK = 100 µA, VSET = 1.00 V 2.0 V ≤ VIN ≤ 5 V 5 V ≤ VIN ≤ 30 V VSAT VIN = 3.0 V, ISW = 650 mA VIN = 5.0 V, ISW = 1 A, TA = +25°C VIN = 5.0 V, ISW = 1 A VIN = 12 V, TA = +25°C, ISW = 650 mA VIN = 12 V, ISW = 650 mA RL = 100 kΩ3 220 Ω from ILIM to VIN TA = +25°C
43 15
SWSAT VOLTAGE, STEP-DOWN MODE
VSAT
1.1 400 1000 400
GAIN BLOCK GAIN CURRENT LIMIT CURRENT LIMIT TEMPERATURE COEFFICIENT SWITCH-OFF LEAKAGE CURRENT MAXIMUM EXCURSION BELOW GND
AV
–0.3 Measured at SW1 Pin TA = +25°C VSW2 ISW1 ≤ 10 µA, Switch Off TA = +25°C 1 –400 10 –350
%/°C µA mV
NOTES 1 This specification guarantees that both the high and low trip points of the comparator fall within the 1.20 V to 1.30 V range. 2 The output voltage waveform will exhibit a sawtooth shape due to the comparator hysteresis. The output voltage on the fixed output versions will always be within the specified range. 3 100 kΩ resistor connected between a 5 V source and the AO pin. Specifications subject to change without notice.
– 2–
REV. 0
ADP1173
ABSOLUTE MAXIMUM RATINGS* PIN CONFIGURATIONS N-8 8-Lead Plastic DIP
ILIM VIN SW1 SW2 1 2 8 FB (SENSE)*
Supply Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 V SW1 Pin Voltage (VSW1) . . . . . . . . . . . . . . . . . . . . . . . . . 50 V SW2 Pin Voltage (VSW2) . . . . . . . . . . . . . . . . . . –0.5 V to VIN Feedback Pin Voltage (ADP1173) . . . . . . . . . . . . . . . . . . . 5 V Sense Pin Voltage (ADP1173, –3.3, –5, –12) . . . . . . . . . 36 V Maximum Power Dissipation . . . . . . . . . . . . . . . . . . 500 mW Maximum Switch Current . . . . . . . . . . . . . . . . . . . . . . . .1.5 A Operating Temperature Range . . . . . . . . . . . . . 0°C to +70°C Storage Temperature Range . . . . . . . . . . . . . –65°C to 150°C Lead Temperature, (Soldering, 10 sec) . . . . . . . . . . . . +300°C
*Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum ratings for extended periods of time may affect device reliability.
SO-8 8-Lead Plastic SO
ILIM VIN SW1 1 2 3 8 FB (SENSE)*
ADP1173
7 SET
ADP1173 7 SET
TOP VIEW (Not to Scale)
TOP VIEW 3 (Not to Scale) 6 AO 4 5 GND
6 AO 5 GND
SW2 4
*FIXED VERSIONS
*FIXED VERSIONS
PIN FUNCTION DESCRIPTIONS
Mnemonic ILIM
Function For normal conditions this pin is connected to VIN. When lower current is required, a resistor should be connected between ILIM and VIN. Limiting the switch current to 400 mA is achieved by connecting a 220 Ω resistor. Input Voltage. Collector Node of Power Transistor. For step-down configuration, connect to VIN; for step-up configuration, connect to an inductor/diode. Emitter Node of Power Transistor. For stepdown configuration, connect to inductor/ diode; for step-up configuration, connect to ground. Do not allow this pin to drop more than a diode drop below ground. Ground. Auxiliary Gain (GB) Output. The open collector can sink 100 µA. Gain Amplifier Input. The amplifier has positive input connected to the SET pin and negative input is connected to 1.245 V reference. On the ADP1173 (adjustable) version this pin is connected to the comparator input. On the ADP1173-3.3, ADP1173-5 and ADP1173-12, the pin goes directly to the internal application resistor that sets the output voltage.
ORDERING GUIDE
Model ADP1173AN ADP1173AR ADP1173AN-3.3 ADP1173AR-3.3 ADP1173AN-5 ADP1173AR-5 ADP1173AN-12 ADP1173AR-12
Output Voltage ADJ ADJ 3.3 V 3.3 V 5V 5V 12 V 12 V
Package Options* N-8 SO-8 N-8 SO-8 N-8 SO-8 N-8 SO-8 VIN SW1
SW2
*N = Plastic DIP, SO = Small Outline Package.
L1* 100µH + 470µF
1
IRF7203 +5V OUTPUT AT 100mA
GND AO SET
56Ω
2
470kΩ SW1 3 AO 6
75kΩ +
ILIM 4X NICAD OR ALKALINE CELLS
7
VIN
ADP1173
SET GND
5
470µF
SW2 FB 8
4
+
470µF
240Ω
FB/SENSE
24kΩ
*L1 = COILTRONICS CTX100-4
Figure 1. Step-Up or Step-Down Converter
CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the ADP1173 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. 0
–3–
ADP1173 –Typical Performance Characteristics
1.2
1.6 1.4
SWITCH ON VOLTAGE – V
1100 1000
1.0
VIN = 3V VIN = 2V
1.2 1.0 0.8 0.6 0.4 0.2
SWITCH CURRENT – mA
VCE(SAT)
900 800 700 600 500 400 300 200 2V < VIN < 5V
VCE (SAT) – V
0.8
0.6 VIN = 5V 0.4
0.2
0 0.2 0.4 0.6 0.8 1.0 SWITCH CURRENT – A 1.2
0.0 0.05
0.15 0.25 0.35 0.45 0.55 0.65 SWITCH CURRENT – A
0.75
100 10
100 RLIM – Ω
1000
Figure 2. Saturation Voltage vs. Switch Current in Step-Up Mode
Figure 3. Switch ON Voltage vs. Switch Current in Step-Down Mode
Figure 4. Maximum Switch Current vs. RLIM in Step-Up Mode
1000 900 VIN =24V WITH L = 500µH @ VOUT = 5V
100 90
SUPPLY CURRENT – mA
120 110
SWITCH CURRENT – mA
800 700 600 500 400 300 200 100 0 100 RLIM – Ω 1000 VIN =12V WITH L = 250µH @ VOUT = 5V
80 70 60 50 40 30 20 10 0 0 100 200 300 400 500 600 700 800 900 SWITCH CURRENT – mA VIN = 2V VIN = 5V
QUIESCENT CURRENT – µA
QUIESCENT CURRENT 100 90 80 70 60 50 40 –40
0
25
70
85
TEMPERATURE – °C
Figure 5. Maximum Switch Current vs. RLIM in Step-Down Mode
Figure 6. Supply Current vs. Switch Current
Figure 7. Quiescent Current vs. Temperature
25.5
80 70 FEEDBACK PIN BIAS CURRENT – nA
450 400 350 300 250 200 VIN = 3V 150 100 50 0 –40 0 25 70 85
OSCILLATOR FREQUENCY – kHz
25 24.5 24 23.5 23 OSCILLATOR FREQUENCY 22.5 22 21.5
SET PIN BIAS CURRENT – nA
60 VIN = 3V 50 40 30 20 10 –40
3
5
20 25 10 15 INPUT VOLTAGE – Volts
30
0
25
70
85
TEMPERATURE – °C
TEMPERATURE – °C
Figure 8. Oscillator Frequency vs. Input Voltage
Figure 9. Set Pin Bias Current vs. Temperature
Figure 10. Feedback Pin Bias Current vs. Temperature
–4–
REV. 0
ADP1173
APPLICATIONS Theory of Operation COMPONENT SELECTION General Notes on Inductor Selection
The ADP1173 is a flexible, low power switch mode power supply (SMPS) controller. The regulated output voltage can be greater than the input voltage (boost or step-up mode) or less than the input (buck or step-down mode). This device uses a gated-oscillator technique to provide very high performance with low quiescent current. A functional block diagram of the ADP1173 is shown on the front page. The internal 1.245 V reference is connected to one input of the comparator, while the other input is externally connected (via the FB pin) to a feedback network connected to the regulated output. When the voltage at the FB pin falls below 1.245 V, the 24 kHz oscillator turns on. A driver amplifier provides base drive to the internal power switch, and the switching action raises the output voltage. When the voltage at the FB pin exceeds 1.245 V, the oscillator is shut off. While the oscillator is off, the ADP1173 quiescent current is only 110 µA. The comparator includes a small amount of hysteresis, which ensures loop stability without requiring external components for frequency compensation. The maximum current in the internal power switch can be set by connecting a resistor between VIN and the ILIM pin. When the maximum current is exceeded, the switch is turned OFF. The current limit circuitry has a time delay of about 2 µs. If an external resistor is not used, connect ILIM to VIN. Further information on ILIM is included in the Limiting the Switch Current section of this data sheet. The ADP1173 internal oscillator provides 23 µs ON and 19 µs OFF times, which is ideal for applications where the ratio between VIN and VOUT is roughly a factor of two (such as converting +3 V to + 5 V). However, wider range conversions (such as generating +12 V from a +5 V supply) can easily be accomplished. An uncommitted gain block on the ADP1173 can be connected as a low battery detector. The inverting input of the gain block is internally connected to the 1.245 V reference. The noninverting input is available at the SET pin. A resistor divider, connected between VIN and GND with the junction connected to the SET pin, causes the AO output to go LOW when the low battery set point is exceeded. The AO output is an open collector NPN transistor which can sink 100 µA. The ADP1173 provides external connections for both the collector and emitter of its internal power switch, which permits both step-up and step-down modes of operation. For the stepup mode, the emitter (pin SW2) is connected to GND and the collector (pin SW1) drives the inductor. For step-down mode, the emitter drives the inductor while the collector is connected to VIN. The output voltage of the ADP1173 is set with two external resistors. Three fixed-voltage models are also available: ADP1173-3.3 (+3.3 V), ADP1173-5 (+5 V) and ADP1173-12 (+12 V). The fixed-voltage models are identical to the ADP1173, except that laser-trimmed voltage-setting resistors are included on the chip. On the fixed-voltage models of the ADP1173, simply connect the feedback pin (Pin 8) directly to the output voltage.
When the ADP1173 internal power switch turns on, current begins to flow in the inductor. Energy is stored in the inductor core while the switch is on, and this stored energy is then transferred to the load when the switch turns off. Both the collector and the emitter of the switch transistor are accessible on the ADP1173, so the output voltage can be higher, lower or of opposite polarity than the input voltage. To specify an inductor for the ADP1173, the proper values of inductance, saturation current and dc resistance must be determined. This process is not difficult, and specific equations for each circuit configuration are provided in this data sheet. In general terms, however, the inductance value must be low enough to store the required amount of energy (when both input voltage and switch ON time are at a minimum) but high enough that the inductor will not saturate when both VIN and switch ON time are at their maximum values. The inductor must also store enough energy to supply the load without saturating. Finally, the dc resistance of the inductor should be low, so that excessive power will not be wasted by heating the windings. For most ADP1173 applications, an inductor of 47 µH to 470 µH, with a saturation current rating of 300 mA to 1 A and dc resistance 6.2 V
where 23 µs is the ADP1173 switch’s “on” time.
VIN R3 100Ω C2 +
1 2 3
If the input voltage to the ADP1173 varies over a wide range, a current limiting resistor at Pin 1 may be required. If a particular circuit requires high peak inductor current with minimum input supply voltage, the peak current may exceed the switch maximum rating and/or saturate the inductor when the supply voltage is at the maximum value. See the Limiting the Switch Current section of this data sheet for specific recommendations.
POSITIVE-TO-NEGATIVE CONVERSION
VOUT
ILIM VIN SW1
FB
8
ADP1173
GND
5
L1 + D1 1N5818 R1
SW2 4 C1
R2
The ADP1173 can convert a positive input voltage to a negative output voltage, as shown in Figure 17. This circuit is essentially identical to the step-down application of Figure 15, except that the “output” side of the inductor is connected to power ground. When the ADP1173’s internal power switch turns off, current flowing in the inductor forces the output (–VOUT) to a negative potential. The ADP1173 will continue to turn the switch on
Figure 15. Step-Down Mode Operation
REV. 0
–9–
ADP1173
until its FB pin is 1.245 V above its GND pin, so the output voltage is determined by the formula:
–V OUT
+VIN R3 C2 +
1 2 3
LIMITING THE SWITCH CURRENT
R1 = 1.245 V × 1+ R2
ILIM VIN SW1
FB 8 L1 + D1 1N5818 R1
ADP1173
GND
5
SW2 4 C1
The ADP1173’s RLIM pin permits the switch current to be limited with a single resistor. This current limiting action occurs on a pulse by pulse basis. This feature allows the input voltage to vary over a wide range, without saturating the inductor or exceeding the maximum switch rating. For example, a particular design may require peak switch current of 800 mA with a 2.0 V input. If VIN rises to 4 V, however, the switch current will exceed 1.6 A. The ADP1173 limits switch current to 1.5 A and thereby protects the switch, but increases the output ripple. Selecting the proper resistor will limit the switch current to 800 mA, even if VIN increases. The relationship between RLIM and maximum switch current is shown in Figures 4 and 5. The ILIM feature is also valuable for controlling inductor current when the ADP1173 goes into continuous-conduction mode. This occurs in the step-up mode when the following condition is met:
V OUT +V DIODE 1 < V IN –V SW 1– DC
R2 –VOUT
Figure 17. A Positive-to-Negative Converter
The design criteria for the step-down application also apply to the positive-to-negative converter. The output voltage should be limited to |6.2 V|, unless a diode is inserted in series with the SW2 Pin (see Figure 16). Also, D1 must again be a Schottky diode to prevent excessive power dissipation in the ADP1173.
NEGATIVE-TO-POSITIVE CONVERSION
The circuit of Figure 18 converts a negative input voltage to a positive output voltage. Operation of this circuit configuration is similar to the step-up topology of Figure 14, except that the current through feedback resistor R1 is level-shifted below ground by a PNP transistor. The voltage across R1 is (VOUT –VBEQ1). However, diode D2 level-shifts the base of Q1 about 0.6 V below ground, thereby cancelling the VBE of Q1. The addition of D2 also reduces the circuit’s output voltage sensitivity to temperature, which otherwise would be dominated by the –2 mV/°C VBE contribution of Q1. The output voltage for this circuit is determined by the formula:
where DC is the ADP1173’s duty cycle. When this relationship exists, the inductor current does not go all the way to zero during the time the switch is OFF. When the switch turns on for the next cycle, the inductor current begins to ramp up from the residual level. If the switch ON time remains constant, the inductor current will increase to a high level (see Figure 19). This increases output ripple, and can require a larger inductor and capacitor. By controlling switch current with the ILIM resistor, output ripple current can be maintained at the design values. Figure 20 illustrates the action of the ILIM circuit.
R1 V OUT = 1.245 V × R2
Unlike the positive step-up converter, the negative-to-positive converter’s output voltage can be either higher or lower than the input voltage.
L1 RLIM +
1 2
1N5818 D1 + R1 Q1 2N3906 1N4148 D2 POSITIVE OUTPUT CL
Figure 19. (ILIM Operation, RLIM = 0 Ω)
C2
ILIM
VIN
SW1 3
ADP1173
FB 8 AO SET GND SW2
6 7 5 4
10kΩ
R2
NEGATIVE INPUT
NC NC
Figure 18. A Negative-to-Positive Converter
Figure 20. (ILIM Operation, RLIM = 240 Ω)
–10–
REV. 0
ADP1173
The internal structure of the ILIM circuit is shown in Figure 21. Q1 is the ADP1173’s internal power switch, which is paralleled by sense transistor Q2. The relative sizes of Q1 and Q2 are scaled so that IQ2 is 0.5% of IQ1. Current flows to Q2 through an internal 80 Ω resistor and through the RLIM resistor. These two resistors parallel the base-emitter junction of the oscillatordisable transistor, Q3. When the voltage across R1 and RLIM exceeds 0.6 V, Q3 turns on and terminates the output pulse. If only the 80 Ω internal resistor is used (i.e., the ILIM pin is connected directly to VIN), the maximum switch current will be 1.5 A. Figures 4 and 5 gives RLIM values for lower current-limit values.
ILIM RLIM (EXTERNAL) VIN R1 Q3 DRIVER OSCILLATOR Q2 Q1 SW2 80Ω (INTERNAL) SW1 +5V
2
R1 VBAT R2
ADP1173
1.245V REF SET GND
5
VIN AO
6
100kΩ TO PROCESSOR
7
R1 =
VLB –1.245V
12.5µA VLB = BATTERY TRIP POINT
R2 = 100kΩ
Figure 22. Setting the Low Battery Detector Trip Point
Figure 22 shows the gain block configured as a low battery monitor. Resistors R1 and R2 should be set to high values to reduce quiescent current, but not so high that bias current in the SET input causes large errors. A value of 100 kΩ for R2 is a good compromise. The value for R1 is then calculated from the formula:
R1 = V LOBATT − 1.245 V 1.245 V R2
Figure 21. Current Limit Operation
where VLOBATT is the desired low battery trip point. Since the gain block output is an open-collector NPN, a pull-up resistor should be connected to the positive logic power supply.
5V
2
The delay through the current limiting circuit is approximately 2 µs. If the switch ON time is reduced to less than 4 µs, accuracy of the current trip-point is reduced. Attempting to program a switch ON time of 2 µs or less will produce spurious responses in the switch ON time. However, the ADP1173 will still provide a properly regulated output voltage.
PROGRAMMING THE GAIN BLOCK
R1 VBAT
ADP1173
1.245mV REF SET GND
VIN AO
6
47kΩ TO PROCESSOR
7
R2
5
The gain block of the ADP1173 can be used as a low-battery detector, error amplifier or linear post regulator. The gain block consists of an op amp with PNP inputs and an open-collector NPN output. The inverting input is internally connected to the ADP1173’s 1.245 V reference, while the noninverting input is available at the SET pin. The NPN output transistor will sink about 100 µA.
R3 1.6MΩ
Figure 23. Adding Hysteresis to the Low Battery Detector
REV. 0
–11–
ADP1173 Typical Circuit Applications
L1* 68µH R1 100Ω
1
2
1N4148
1
100Ω
2
2 x 1.5V CELLS
ILIM
VIN SW1 3 FB 8
2.21MΩ 1% 4.7µF 118kΩ 1% 0.1µF
9V BATTERY
ILIM
VIN
SW1 3
ADP1173-5
GND
5
ADP1173
GND SW2
5 4
SENSE 8 SW2
4
L1* 47µH 100µF +
1N5818
1N5818
1N5818
5V OUTPUT 150mA AT 9V INPUT 50mA AT 6.5V INPUT
*L1 = GOWANDA GA10-682K COILTRONICS CTX68-4 FOR 5V INPUT CHANGE R1 TO 47Ω CONVERTER WILL DELIVER –22V AT 40mA
22µF
220kΩ –22V OUTPUT 7mA AT 2.0V INPUT 70% EFFICIENCY
*L1 = GOWANDA GA10-472K COILTRONICS CTX50-1 FOR HIGHER OUTPUT CURRENTS SEE ADP1073 DATASHEET
Figure 27. 9 V to 5 V Converter
Figure 24. 3 V–22 V LCD Bias Generator
+VIN 12V-28V 100Ω
1
2
L1* 82µH
ILIM
1
2
VIN
SW1 3
ADP1173-5
SW1 3 1N5818
8
2 x 1.5V CELLS
ILIM
VIN
ADP1173-5
GND
5
GND
SENSE 8 SW2
4
SW2
4
SENSE
+
5V OUTPUT 150mA AT 3V INPUT 60mA AT 2V INPUT
5
L1* 220µH 100µF + 5V OUTPUT 300mA
100µF
1N5818 *L1 = GOWANDA GA10-223K
*L1 = GOWANDA GA10-822K
Figure 25. 3 V to 5 V Step-Up Converter
Figure 28. +20 V to 5 V Step-Down Converter
+VIN 5V INPUT
+ 22µF
1
100Ω
2
ILIM
VIN
SW1 3
ADP1173-5
GND
5
SENSE 8 SW2
4
L1* 100µH + 100µF –5V OUTPUT 75mA
1N5818 *L1 = GOWANDA GA10-103K COILTRONICS CTX100-1
Figure 26. +5 V to –5 V Converter
–12–
REV. 0
ADP1173
44mH 48V DC 44mH L1* 500µH MUR110 +5V 100mA 390kΩ 2N5400 IRF530 100Ω
1 2
~ ~
+ + – 47µF 100V 3.6MΩ 10kΩ 15V 1N4148 VN2222L 12V + 220µF 10V
*L1 = CTX110077 IQ = 120µA
10nF
ILIM 1N965B + 10µF 16V
VIN
SW1 3
ADP1173
GND
5
SW2
4
FB 8 110kΩ
Figure 29. Telecom Supply
L1* 100µH
1N5818
SI9405DY VOUT = 5V AT 100mA AT VIN = 2.6V
56Ω + 470µF 4 x NICAD OR ALKALINE CELLS
7 1
2
470kΩ SW1 3 AO 6 FB 8 470µF + 240Ω
75k +
ILIM SET
VIN
ADP1173
SW2
4 5
470µF
GND
24kΩ
*L1 = GOWANDA GA20-103K COILTRONICS CTX100-4 VIN = 2.6V TO 7.2V
Figure 30. 5 V to 5 V Step-Up or Step-Down Converter
L1* 20µH, 5A
1N5820
47kΩ 100kΩ 470µF + 2N3906 2.2MΩ 2 x NICAD
100kΩ
1 6
2
220Ω 100Ω SW1 3 301kΩ† FB 8 2N4403 +5V OUTPUT 200mA LOCKOUT AT 1.85V INPUT 5Ω MJE200 100kΩ† 47Ω + 470µF
AO
ILIM
VIN
ADP1173
7
SET GND
5
SW2
4
100kΩ
*L1 = COILTRONICS CTX-20-5-52 †1% METAL FILM
Figure 31. 2 V to 5 V at 200 mA Step-Up Converter with Undervoltage Lockout
REV. 0
–13–
ADP1173
VIN 7V-24V
1
0.22Ω 1N5818
2
MTM20P08 18V 1W 2kΩ 2N3904 100Ω 1/2W 51Ω
L1* 25µH, 2A 1N5820 + 470µF –VOUT = –5.13*VC
ILIM
VIN SW1 3
ADP1173
GND
5
1N4148 VIN 200kΩ
39k Ω VC (0V TO +5V)
SW2
4
FB 8
OP196
*L1 = GOWANDA GT10-100 EFFICIENCY ≥ 80% FOR 10mA ≤ ILOAD ≤ 500mA STANDBY IQ ≤ 150µA
Figure 32. Voltage Controlled Positive-to-Negative Converter
VIN 7V-24V
1
0.22Ω 1N5818
2
MTM20P08 18V 1W 2kΩ 2N3904 100Ω 1/2W 51Ω
L1* 25µH, 2A 1N5820 + 470µF 5V 500mA
ILIM
VIN SW1 3
ADP1173
GND
5
1N4148 121k Ω 40.2kΩ
SW2
4
FB 8
OPERATE STANDBY
*L1 = GOWANDA GT10-100 EFFICIENCY ≥ 80% FOR 10mA ≤ ILOAD ≤ 500mA STANDBY IQ ≤ 150µA
Figure 33. High Power, Low Quiescent Current Step-Down Converter
–14–
REV. 0
ADP1173
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Lead Plastic DIP (N-8)
0.430 (10.92) 0.348 (8.84)
8 5
0.280 (7.11) 0.240 (6.10)
1 4
PIN 1 0.210 (5.33) MAX 0.160 (4.06) 0.115 (2.93)
0.060 (1.52) 0.015 (0.38) 0.130 (3.30) MIN SEATING PLANE
0.325 (8.25) 0.300 (7.62) 0.195 (4.95) 0.115 (2.93)
0.022 (0.558) 0.100 0.070 (1.77) 0.014 (0.356) (2.54) 0.045 (1.15) BSC
0.015 (0.381) 0.008 (0.204)
8-Lead Small Outline Package (SO-8)
0.1968 (5.00) 0.1890 (4.80)
8 1 5 4
0.1574 (4.00) 0.1497 (3.80)
0.2440 (6.20) 0.2284 (5.80)
PIN 1 0.0098 (0.25) 0.0040 (0.10)
0.0688 (1.75) 0.0532 (1.35)
0.0196 (0.50) x 45° 0.0099 (0.25)
SEATING PLANE
0.0500 0.0192 (0.49) (1.27) 0.0138 (0.35) BSC
0.0098 (0.25) 0.0075 (0.19)
8° 0°
0.0500 (1.27) 0.0160 (0.41)
REV. 0
–15–
– 16–
C2965–12–1/97
PRINTED IN U.S.A.