S-8521F25MC-BPKT2G Seiko Instruments, S-8521F25MC-BPKT2G Datasheet

no-image

S-8521F25MC-BPKT2G

Manufacturer Part Number
S-8521F25MC-BPKT2G
Description
IC REG PWM/PFM 300KHZ SOT23-5
Manufacturer
Seiko Instruments
Type
Step-Down (Buck)r
Datasheet

Specifications of S-8521F25MC-BPKT2G

Internal Switch(s)
No
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
2.5V
Current - Output
120mA
Frequency - Switching
300kHz
Voltage - Input
2.5 ~ 16 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
SOT-23-5, SC-74A, SOT-25
Power - Output
250mW
Output Voltage
2.5 V
Input Voltage
2.5 V to 16 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
© Seiko Instruments Inc., 1997-2010
The S-8520/8521 Series is a CMOS step-down switching regulator-controller with PWM control (S-8520 Series) and PWM
/ PFM switching control (S-8521 Series). The S-8520/8521 Series has a reference voltage source, an oscillation circuit, an
error amplifier, and other components.
The S-8520 Series provides low-ripple power, high efficiency, and excellent transient characteristics due to a PWM control
circuit capable of varying the duty ratio linearly from 0% up to 100%. The S-8520/8521 Series also has a soft-start circuit
that prevents overshoot at startup.
The S-8521 Series works with either PWM control or PFM control. It normally operates using PWM control with a duty ratio
of 25% to 100%, but under a light load, it automatically switches to PFM control with a duty ratio of 25%. The S-8520/8521
Series ensures high efficiency over a wide range of conditions for devices, from the standby mode to the operation.
By adding external Pch power MOS FET or PNP transistor, coil, capacitor, and externally connected diode, the
S-8520/8521 Series can function as a step-down switching regulator, and is ideal for power supply units of portable
devices due to small SOT-23-5 and the feature of low current consumption. It is also ideal for AC adapters due to the input
voltage up to 16 V.
www.sii-ic.com
Features
• Low current consumption
• Input voltage:
• Output voltage:
• Duty ratio:
• External parts are Pch power MOS FET or PNP transistor, coil, diode, and capacitor only
• Oscillation frequency:
• Soft-start function:
• With a shutdown function
• With a built-in overload protection circuit Overload detection time:
• Lead-free, Sn 100%, halogen-free
*1. Refer to “ Product Name Structure” for details.
(When using PNP transistor, add base resistor and capacitor).
During operation: 60 μA max. (A, B types)
During shutdown: 0.5 μA max.
2.5 V to 16 V (B, D, F types)
2.5 V to 10 V (A, C, E types)
Selectable between 1.5 V and 6.0 V in 0.1 V step
0% to 100% PWM control (S-8520 Series)
25% to100% PWM / PFM switching control (S-8521 Series)
180 kHz typ. (A, B types)
60 kHz typ.
300 kHz typ. (E, F types)
8 ms. typ.
12 ms. typ.
4.5 ms. typ.
STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE
*1
(A, B types)
(C, D types)
(E, F types)
(C, D types)
Seiko Instruments Inc.
21 μA max. (C, D types)
100 μA max. (E, F types)
SWITCHING REGULATOR CONTROLLER
S-8520/8521 Series
4 ms. typ.
14 ms. typ.
2.6 ms. typ.
(A type)
(C type)
(E type)
Rev.9.0
_00
1

Related parts for S-8521F25MC-BPKT2G

S-8521F25MC-BPKT2G Summary of contents

Page 1

... The S-8521 Series works with either PWM control or PFM control. It normally operates using PWM control with a duty ratio of 25% to 100%, but under a light load, it automatically switches to PFM control with a duty ratio of 25%. The S-8520/8521 Series ensures high efficiency over a wide range of conditions for devices, from the standby mode to the operation. ...

Page 2

... Power supplies for audio equipment, including portable CD players and headphone stereo equipment. • Fixed voltage power supply for cameras, video and communication devices. • Power supplies for microcomputers • Conversion from NiH or four NiCd cells or two lithium-ion cells to 3 • Conversion of AC adapter input Package • ...

Page 3

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 Block Diagrams 1. S-8520 Series Remark All the diodes in the figure are parasitic diodes. 2. S-8521 Series Remark All the diodes in the figure are parasitic diodes. VIN Oscillation circuit EXT PWM control ...

Page 4

... The control types, product types, and output voltage for the S-8520/8521 Series can be selected at the user’s request. Please refer to the “1. Product name” for the definition of the product name, “2. Package” regarding the package drawings and “3. Product name list” for the full product names. ...

Page 5

... S-8520D36MC-BVVT2x 4.0 4.5 5.0 S-8520D50MC-BWJT2x 5.2 5.5 6.0 Remark 1. Please contact our sales office for products with output voltage other than those specified above Please select products of environmental code = U for Sn 100%, halogen-free products. Table S-8520AxxMC Series S-8520BxxMC Series − S-8520B15MC-ARAT2x − ...

Page 6

... Remark 1. Please contact our sales office for products with output voltage other than those specified above Please select products of environmental code = U for Sn 100%, halogen-free products. 6 Table S-8521AxxMC Series S-8521BxxMC Series − S-8521B15MC-ATAT2x − ...

Page 7

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 Pin Configuration SOT-23-5 Top view Figure 3 Table 3 Pin No. Symbol Shutdown pin “H”: ______ 1 ON/OFF “L”: 2 VSS GND pin 3 VOUT Output voltage monitoring pin 4 EXT Connection pin for external transistor ...

Page 8

... Board size : (2) Board name : JEDEC STANDARD51-7 Caution The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. (1) When mounted on board 700 600 ...

Page 9

... Time until the EXT pin reaches V dropping OUT − Sumida Corporation CD54 (47 μH) Matsushita Electric Industrial Co., Ltd. MA720 (Shottky type) Matsushita Electric Industrial Co., Ltd μF tantalum type) Toshiba Corporation 2SA1213 ): 0.68 kΩ 2200 pF (Ceramic type) b ______ pin to the VIN pin. ...

Page 10

... Time until the EXT pin reaches V dropping OUT − Sumida Corporation CD54 (47 μH) Matsushita Electric Industrial Co., Ltd. MA720 (Shottky type) Matsushita Electric Industrial Co., Ltd μF tantalum type) Toshiba Corporation 2SA1213 ): 0.68 kΩ 2200 pF (Ceramic type) b ______ pin to the VIN pin. ...

Page 11

... Time until the EXT pin reaches V dropping OUT − Sumida Corporation CD54 (47 μH) Matsushita Electric Industrial Co., Ltd. MA720 (Shottky type) Matsushita Electric Industrial Co., Ltd μF tantalum type) Toshiba Corporation 2SA1213 ): 0.68 kΩ 2200 pF (Ceramic type) b ______ pin to the VIN pin. ...

Page 12

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series Test Circuit − − 12 open open EXT VOUT VIN ______ ON/OFF VSS Figure 5 VIN EXT VOUT ______ ON/OFF VSS Figure 6 0.68 kΩ 2200 pF EXT VIN VOUT ______ ON/OFF VSS Figure 7 Seiko Instruments Inc ...

Page 13

... The S-8521 Series operates under PWM control with the pulse width duty changing from 25 to 100 high output load current area. The S-8521 Series operates under PFM control with the pulse width duty fixed at 25%, and pulses are skipped according to the load current ...

Page 14

... ON/OFF prevents the output voltage from overshooting. However, the soft-start function of this IC is not able to perfectly prevent a rush current from flowing to the load (Refer to Figure 8). Since this rush current depends on the input voltage and load conditions, Perform sufficient evaluation with actual device for design ...

Page 15

... ON continually to supply current to the load, even in cases where the input voltage drops to the set value of output voltage or less. The output voltage in this case is; the voltage subtracting both of the inductance’s DC resistance and the voltage drop by the switching resistor’ ...

Page 16

... Oscillation frequencies Either oscillation frequency, 180 kHz (A and B types), 60 kHz (C and D types), or 300 kHz (E and F types), can be selected. The and F types have high oscillation frequency, how ripple voltage and excellent transient response characteristics ...

Page 17

... But in case of supplying current to load by using 100% duty cycle, select the S-8520/8521 Series without the overload protection circuit (B, D and F types), according to the conditions of application. The operation voltage differs (A, B and E types (B, D and F types) whether the overload protection circuit is available or not. ...

Page 18

... OUT The loss the switching transistor decreases by increasing L and the efficiency becomes the maximum certain L value. Further increasing L value decreases the efficiency due to the loss of the direct current resistance of the coil. I also decreases. OUT For the S-8520/8521 Series, increasing the inductance value, the output voltage may be unstable in some cases, depending on the conditions of the input voltage, output voltage, and the load current ...

Page 19

... The total gate capacity and the on-resistance affect efficiency. Power dissipation when charging and discharging the gate capacity by switching operation affects efficiency, in the area of low load current, as the total gate capacity is larger and the input voltage is higher. Select a MOS FET with a small total gate capacity for efficiency at light load. ...

Page 20

... A small R value increases the output current, but it also decreases efficiency. Determine the optimum value b through experiment, since the base current may flow on the pulse, or voltage may drop due to wiring resistance. In addition, if speed-up capacitor C switching will be reduced, leading to higher efficiency. Determine the C ...

Page 21

... EXT + ______ ON/OFF Caution The above connection diagram and constant will not guarantee successful operation. Perform through evaluation using the actual application to set the constant. L Oscillation Reference voltage circuit source with soft start PWM control or PWM / PFM switching control circuit ______ ...

Page 22

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series Precautions • Mount the external capacitors, the diode and the coil as close as possible to the IC, and secure grounding at a single location. • Characteristics ripple voltage and spike noise occur in IC containing switching regulators. Moreover, rush current flows at the time of a power supply injection ...

Page 23

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 Application Circuits 1. External adjustment of output voltage In the S-8550/8521 Series, by adding external resistors (R adjusted or be set freely in the range of 1 shown in Figure 14. Temperature gradient can be given by inserting a thermistor in series to R EXT VIN PWM control or PWM / + PFM switching control unit − ...

Page 24

... R On the other hand, a reactive current flows through R negligible value with respect to the load current in the actual use of the IC so that the efficiency characteristics will not be degraded. This requires that the value of R However, too large a value (more than 1 MΩ) for the R Check the influence of this value on actual equipment ...

Page 25

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 Characteristics (Typical Data) 1. Examples of major parameters characteristics (1) Current consumption (I SS1 −40° [ +85° +25° (2) Oscillation frequency (f osc [V] IN 360 340 320 300 280 260 240 )-Input voltage ( kHz) osc +25° ...

Page 26

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series (3) EXT pin output current “H” (I Input voltage ( −60 −50 −40 −30 −20 − (5) Soft start time (t )-Input voltage ( [ [ (4) EXT pin output current “L” (I EXTH Input voltage ( −40° +25° ...

Page 27

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 (6) Overload detection time (t pro +85° −40° +25° [ +85° +25° −40° [V] IN ______ (7) ON/OFF pin input voltage “H” (V Input voltage ( 1.8 1 −40°C 1 +25°C 1.2 1.0 0 +85° ...

Page 28

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series (9) Output voltage (V )-Input voltage (V OUT S-8521B30MC 3.08 3.07 I OUT 3. 500 mA OUT 3.05 3.04 3.03 3.02 3.01 3.00 2.99 2. S-8521F33MC 3.38 3.37 I 3.36 OUT I 3.35 OUT 3.34 3.33 3.32 3.31 3.30 3 ...

Page 29

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 2. Transient Response Characteristics 2. 1 Power- load) OUT (1) S-8520/8521C30MC [2.5 V/div OUT [1 V/div ms/div] (2) S-8520/8521A30MC [2.5 V/div OUT [1 V/div ms/div] (3) S-8520/8521E33MC [2.5 V/div OUT [1 V/div ms/div V→3 [2.5 V/div OUT [1 V/div] ...

Page 30

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series 2. 2 Shutdown pin response (V (1) S-8520/8521C30MC OFF [1 V/div OUT [1 V/div ms/div] (2) S-8520/8521A30MC OFF [1 V/div OUT [1 V/div ms/div] (3) S-8520/8521E33MC OFF [1 V/div OUT [1 V/div ms/div] 30 ______ = 0 V→1 load) ON/OFF OUT (V = 3.6 V) ...

Page 31

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 2. 3 Supply voltage variation (V (1) S-8520/8521C30MC [2.5 V/div OUT [0.2 V/div] t [0.5 ms/div] (3) S-8520/8521A30MC [2.5 V/div OUT [0.2 V/div] t [0.5 ms/div] (5) S-8520/8521E33MC [2.5 V/div OUT [0.2 V/div] t [0.5 ms/div V→ V→4 V) ...

Page 32

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series 2. 4 Load variation (1) S-8520/8521C30MC ( 500 mA I OUT 0 OUT [0.1 V/div] t [0.1 ms/div] (2) S-8520/8521A30MC ( 500 mA I OUT 0 OUT [0.1 V/div] t [0.1 ms/div] (3) S-8520/8521E33MC ( 500 mA I OUT 0 OUT [0.1 V/div ...

Page 33

... Rev.9.0 _00 Reference Data This reference data is intended to help you select peripheral components to be externally connected to the IC. Therefore, this information provides recommendations on external components selected with a view to accommodating a wide variety of IC applications. Characteristic data is duly indicated in the table below. Product name Output voltage CD105 / 47 μ ...

Page 34

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series Product name Output voltage S-8520D30MC S-8521D30MC 3.0 V S-8520B30MC S-8521B30MC S-8520F33MC 3.3 V S-8521F33MC S-8520D50MC S-8521D50MC S-8520B50MC 5.0 V S-8521B50MC S-8520F50MC S-8521F50MC Component Product name CD54 CD105 Inductor CDH113 D62F MA720 Diode MA737 ...

Page 35

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 1. Efficiency Characteristics: Output current (I (1) S-8520B30MC (CD105 / 47 μH, TM6201) 100 0.01 0 [mA] OUT (2) S-8520F33MC (D62F / 22 μH, TM6201) 100 0.01 0 OUT (3) S-8521D30MC (CD54 / 47 μH, TM6201) 100 0.01 0 [mA] OUT (4) S-8521B30MC (CD105 / 47 μH, TM6201) ...

Page 36

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series (5) S-8521F33MC (D62F / 22 μH, TM6201) 100 0.01 0 [mA] OUT (6) S-8520B50MC (CD54 / 47 μH, TM6201) 100 0.01 0 [mA] OUT (7) S-8520F50MC (D62F / 22 μH, TM6201) 100 0.01 0 [mA] OUT (8) S-8521D50MC (CD54 / 47 μH, TM6201) 100 90 80 ...

Page 37

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 (9) S-8521B50MC (CD54 / 47 μH, TM6201) 100 0.01 0 [mA] OUT (10) S-8521F50MC (D62F / 22 μH, TM6201) 100 0.01 0 [mA] OUT 100 6 9 0.01 10 100 1000 100 0.01 10 100 1000 Seiko Instruments Inc. S-8520/8521 Series (CD105 / 47 μ ...

Page 38

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series 2. Ripple Voltage Characteristics: Ripple voltage (V SBD: MA720) (1) S-8520D30MC 240 200 I = 500 mA OUT I = 100 mA OUT 160 I = 0.1 mA OUT 120 (3) S-8520B30MC 240 200 = 500 mA I OUT 160 I = 100 mA OUT I = 0.1 mA 120 OUT ...

Page 39

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.9.0 _00 (9) S-8520B50MC 240 200 I = 500 mA OUT 160 I = 100 mA OUT 120 I = 0.1 mA OUT [V] IN (11) S-8520F50MC 240 200 I = 500 mA OUT I = 100 mA OUT 160 I = 0.1 mA OUT 120 [V] IN (10) S-8521B50MC = 22 μF×2) (C OUT 240 200 ...

Page 40

... STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8520/8521 Series 3. PWM / PFM switching characteristics: Input voltage (V (1) S-8521D30MC OUT (3) S-8521F33MC OUT (5) S-8521B50MC OUT 40 IN (2) S-8521B30MC 14 10 100 1000 [mA] (4) S-8521D50MC 14 10 100 1000 [mA] (6) S-8521F50MC 14 10 100 1000 [mA] Seiko Instruments Inc. ...

Page 41

...

Page 42

...

Page 43

...

Page 44

... Seiko Instruments Inc. is strictly prohibited. • The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Seiko Instruments Inc. ...

Related keywords