Document
Rev.2.3_00 www.DataSheet4U.com
STEP-DOWN, SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER
S-8533 Series
The S-8533 Series is a synchronous PWM control CMOS step-down switching regulator controller that includes a reference voltage source, synchronous circuit, oscillation circuit, error amplifier, phase compensation circuit, and PWM controller. An efficient step-down switching regulator can be realized simply by adding external P-channel and N-channel power MOS FETs, one coil, and three capacitors. Since the oscillation frequency is a high 300 kHz, the S-8533 can be used to configure a high efficiency step-down switching regulator capable of driving high output current using small external parts and a 3 to 10% increase in efficiency is obtained compared to conventional step-down switching regulators. The 8-Pin TSSOP package and high oscillation frequency make the S8533 ideal as the main power supply for portable devices.
Features
• Synchronous rectification system realizing high efficiency (typ. 94%) • Use at maximum duty ratio = 100% and use of a battery up to maximum life is possible by using P-channel and Nchannel power MOS FETs externally. • Oscillation frequency : 300 kHz typ. • Input voltage : 2.7 to 16.0 V • Output voltage : 1.25 V 1.3 to 6.0 V, selectable in 0.1 V steps • Output voltage accuracy : ±2.0% • Soft-start function set by an external capacitor (CSS) • Shutdown function • Small package : 8-Pin TSSOP • Lead-free products
Applications
• • • • Constant voltage power supply for hard disks and DVD drivers Power supplies for portable devices, such as digital cameras, PDAs, electronic organizers, and cellular phones Main or sub power supply for notebook PCs and peripherals Constant voltage power supply for cameras, video equipment, and communication equipment
Package
Package Name 8-Pin TSSOP Package FT008-A Drawing Code Tape FT008-E Reel FT008-E
Seiko Instruments Inc.
1
STEP-DOWN, www.DataSheet4U.com
SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER Rev.2.3_00 S-8533 Series
Block Diagram
L VIN
Oscillation circuit
Tr
VOUT
PDRV
+
PWM control circuit P.N feed-through prevention circuit
− +
COUT
+
VIN CIN CSS Tr
NDRV
CSS
Reference voltage source with soft start
VSS
ON / OFF
Remark All the diodes in the figure are parasitic diodes.
Figure 1
2
Seiko Instruments Inc.
STEP-DOWN, www.DataSheet4U.com Rev.2.3_00
SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER S-8533 Series
Product Name Structure
The output voltage for the S-8533 Series can be selected depending on usage. Refer to “1. Product name” for the definition of the product name and “2. Product name list” for the full product names.
1. Product Name
S-8533A xx x FT − TB − G IC direction in tape specifications*1 Package code FT : 8-Pin TSSOP Output voltage A : 1.3 to 6.0 V 5 : 1.25 V Output voltage 13 to 60 (E.g., when the output voltage is 1.5 V, it is expressed as 15.) The product whose output voltage is 1.25 V expresses 12. *1. Refer to the taping specifications.
2. Product Name List
Output Voltage Product Name 1.25 V S-8533A125FT-TB-G 1.3 V S-8533A13AFT-TB-G 1.4 V S-8533A14AFT-TB-G 1.5 V S-8533A15AFT-TB-G 1.8 V S-8533A18AFT-TB-G 2.5 V S-8533A25AFT-TB-G 2.7 V S-8533A27AFT-TB-G 2.8 V S-8533A28AFT-TB-G 3.0 V S-8533A30AFT-TB-G 3.3 V S-8533A33AFT-TB-G 3.9 V S-8533A39AFT-TB-G 4.1 V S-8533A41AFT-TB-G 4.5 V S-8533A45AFT-TB-G 4.8 V S-8533A48AFT-TB-G 4.9 V S-8533A49AFT-TB-G 5.0 V S-8533A50AFT-TB-G 5.5 V S-8533A55AFT-TB-G 6.0 V S-8533A60AFT-TB-G Remark Contact the SII marketing department for the availability of product samples other than those specified above.
Seiko Instruments Inc.
3
STEP-DOWN, www.DataSheet4U.com
SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER Rev.2.3_00 S-8533 Series
Pin Configurations
Table 1
8-Pin TSSOP Top view 1 2 3 4 8 7 6 5
Figure 2
No connection Output voltage pin Shutdown pin H : Normal operation (step-down operation) 3 ON/ OFF L : Step-down operation stopped (all circuits deactivated) 4 CSS Soft start capacitor connection pin 5 VSS GND pin 6 NDRV External N-channel connection pin 7 PDRV External P-channel connection pin 8 VIN IC power supply pin *1. The NC pin is electrically open. Connection of this pin to VIN or VSS is allowed.
Pin No. 1 2
Symbol NC*1 VOUT
Pin Description
4
Seiko Instruments Inc.
STEP-DOWN, www.DataSheet4U.com Rev.2.3_00
SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER S-8533 Series
Absolute Maximum Ratings
Table 2
Parameter VIN pin voltage VOUT pin voltage ON/OFF pin voltage CSS pin voltage NDRV pin voltage PDRV pin voltage NDRV pin current PDRV pin current Power dissipation Symbol VIN VOUT VON/OFF VCSS VNDRV VPDRV INDRV IPDRV PD (Ta = 25°C unless otherwise specified) Absolute Maximum Rating Unit VSS − 0.3 to VSS + 18 V VSS − 0.3 to VSS + 18 V VSS − 0.3 to VSS + 18 V VSS − 0.3 to VIN + 0.3 V VSS − 0.3 to VIN + 0.3 V VSS − 0.3 to VIN + 0.3 V ±100 mA ±100 mA 300 (When not mounted on board) mW 700*1 mW −40 to +85 °C −40 to +.