S-8550 Datasheet, PDF (5/26 Pages) Seiko Instruments Inc – STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECIFICATION, PWM CONTROL SWITCHING REGULATORS

STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECTIFICATION, PWM CONTROL SWITCHING REGULATORS
Rev.2.1_01
S-8550/8551 Series
„ Absolute Maximum Ratings
Table 3 Absolute Maximum Ratings
(Unless otherwise specified: Ta = 25°C, V_SS = 0 V)
Parameter
Symbol
Absolute Maximum Rating
Unit
VIN pin voltage
FB pin voltage
CONT pin voltage
ON/OFF pin voltage
CONT pin current
Power dissipation
Operating temperature
Storage temperature
V_IN
V_FB
V_CONT
VON/OFF
I_CONT
P_D
T_opr
T_stg
V_SS − 0.3 to V_SS + 6.0
V
V_SS − 0.3 to V_IN + 0.3
V
V_SS − 0.3 to V_IN + 0.3
V
V_SS − 0.3 to V_IN + 0.3
V
1300
mA
600^*1
mW
−40 to +85
°C
−40 to +125
°C
*1. When mounted on printed circuit board
[Mounted board]
(1) Board size: 114.3 mm × 76.2 mm × t1.6 mm
(2) Board name: JEDEC STANDARD51-7
Caution
1. 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.
2. Since this IC has a built-in power MOS FET, make sure that dissipation of the power MOS FET
does not exceed the allowable power dissipation of the package. (Refer to Figure 3.)
Generally, dissipation of a switching regulator can be calculated by the following equation.
Dissipation = (100 (%) − efficiency (%)) / efficiency (%) × output voltage × load current
The greater part of dissipation depends on the built-in power MOS FET, however, dissipation
of the inductor is also included.
In addition, since power dissipation of the package also changes according to a mounting
board or a mounting state, fully check them using an actually mounted mode.
700
600
500
400
300
200
100
0
0
50
100
150
Ambient temperature (Ta) [°C]
Figure 3 Power Dissipation of Package (Mounted on Board)
Seiko Instruments Inc.
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