Document
DC/DC Step-Down Converter IC
SI-8000TM Series
September 2005
■General Descriptions
SI-8000TM series has 300kHz oscillation frequency, so it contributes miniaturization of a chalk coil. Therefore, it realizes a compact and high efficient power supply together with TO 252-5 package (compatible:SC-63) . SI-8000TM series has the function required for switching regulators and protection circuits such as over-current, and overheating. With only four discrete components, it realizes a high efficient switching regulator without adjustment. 1.5A output current by compact power surface mount package.
■Package---TO252-5
■Applications
●DVD Recorder、FPD TV ●OA equipment, such as a printer ●On-board local power supply
■Key Specifications
■Features
●1.5A output current by compact power surface mount package. ● High Efficiency 81% (at VIN=15V, Io=0.5A,Vo=5V) ● Requires only four discrete components. (C3: required for soft
start.) ●Built-in Oscillation circuit
(oscillation frequency : 300kHz (TYP)) ●Constant current type overcurrent protection and overheating
protection. ●Soft start function. (ON/OFF function available. Output OFF at
Low level.) ● Low consumption current at Output OFF.
Input Voltage Output Current
Output Voltage
Efficiency (TYP)
SI-8008T M
(ADJ Type)
0.8V
(REF Voltage)
81%
(5V Set-up)
Typical Connection
SI-8033T M
SI-8050T M
43V
0 to 1.5A
3.3V 5.0V
76% 81%
SI-8120T M
12.0V 87%
C1:220μF C2:470μF C3:1μF
(At the time of soft start functional use)
L1:47μH Di:SFPB66(Sanken)
.
Sanken Electric Co.,Ltd.
http://www.sanken-ele.co.jp/en/
1/15
I02-001EA-050910
DC/DC Step-Down Converter IC
SI-8000TM Series
September 2005
1. Scope
The present specifications shall apply to a DC-DC buck converter SI-8008TM.
2. Outline
Classification Semiconductor IC (monolithic IC)
Structure
Plastic package (transfer mold)
Applications
・DC voltage regulator ・Power supplies for telecommunication equipment , office equipment etc ,ON-board local regulator ・Output voltage regulator at secondary stage of switch mode power supply
3. Absolute maximum ratings
3-1 Absolute maximum ratings
Characteristic DC input voltage Power dissipation 1 Power dissipation2
Junction temperature
Storage temperature Thermal resistance (junction-case) Thermal resistance (junction-ambient air)
Symbol VIN Pd1 Pd2
Tj
Tstg θj-c θj-a
Ratings 43
1.06 1.65
-40~150
-40~150 6 95
Units
Remarks
V W W
℃
℃ ℃/W ℃/W
Glass‐epoxy board mounting in 900square ㎜, copper area 4.3% Tjmax=125℃ Glass‐epoxy board mounting in 900square ㎜, copper area 50% Tjmax=125℃ Thermal protection circuit is built-in in this product and when junction temperature rises to 130℃ or higher, it may be caused to operate
Recommended max. junction temperature at operation is 125℃.
Glass‐epoxy board mounting in 900square ㎜, copper area 4.3%
.
Sanken Electric Co.,Ltd.
2/15
I02-001EA-050910
DC/DC Step-Down Converter IC
SI-8000TM Series
September 2005
3-2 Recommended operating conditions
Characteristic
Symbol
DC input voltage range
DC output voltage range DC output current range Operating junction temperature
range Operating temperature range
VIN Vo Io Tjop Top
Ratings
MIN
MAX
*1 Vo+3
40
0.8~24 0~1.5 -40~125 -40~125
Units V V A ℃ ℃
Remarks Io=0~1.5A
*2 VIN≧Vo+3V *2
*1 The minimum value of DC input voltage range is 8V when output is less than 5V, VO+3,when the output is more than 5V.In the case of VIN=Vo+2~Vo+3V , it is set to Io=1A MAX.
*2 To be used within the allowable package power dissipation characteristics (refer to P6).
4. Electrical characteristics
4-1 Electrical characteristics (Ta=25℃、Vo=5V adjusted R1=4.2kΩ,R2=0.8kΩ)
Characteristic
Symbol
MIN
Limits TYP
MAX
Reference voltage
VADJ
0.784 0.800 0.816
Units V
Reference voltage temperature coefficient ⊿VREF/⊿T
±0.1
mV/℃
Efficiency *3
η 81 %
Operating frequency
fo 300 kHz
Test conditions
VIN=15V,IO=0.1A
VIN=15V IO=0.1A,Tc=0~100℃
VIN=15V,IO=0.5A
,
VIN=15V,IO=0.5A
Line regulation
VLine
60 80 mV VIN=10~30V,IO=0.5A
Load regulation
VLoad
10 40 mV VIN=15V,IO=0.2~1.5A
Over current protection starting current
IS 1.6
A VIN=15V
ON/OFF terminal *4
Low level voltage Flow-out current at low level voltage
Quiescent current 1
Quiescent current 2
VSSL ISSL Iq Iq(off)
0.5 V
10 40 μA VSSL=0V
6 mA VIN=15V,IO=0A
200
400
μA
VIN=15V VSS=0V
Sanken Electric Co.,Ltd.
3/15
I02-001EA-050910
DC/DC Step-Down Converter IC
SI-8000TM Series
September 2005
*3 Efficiency is calculated by the following equation.
η(%)=
VO・IO VIN・IIN
×100
*4 No.5 terminal is a SS terminal to enable soft start by connecting a capacitor. The output can be turned on and off by using a SS terminal. The output is stopped by decreasing the SS terminal voltage below VSSL and in order to perform ON/OFF operation of Vout, it is required to connect NPN transistor or the output of open collector type TTL between No.5 terminal
and GND. In case that both soft and Vout ON/OFF are used, a protection measure such as limitation of.