SI9174 Datasheet, PDF (2/17 Pages) Vishay Siliconix – High Performance Step-Down DC-DC Converter With Dynamically Adjustable Output Voltage

Si9174
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to AGND = 0 V
V_IN, V_DD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 V
Lx, SD, MODE, FB, DAC, SYNC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to 6.2 V
(or to V_DD )0.3 V whichever is less)
GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to +0.3 V
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 kV
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65 to 125_C
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150_C
Power Dissipation (Package)^a
10-pin MSOP^b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 mW
10-pin MLP33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 915 mW
Thermal Impedance (Q_JA)
10-Pin MSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135_C/W
10-Pin MLP33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71_C/W
Peak Inductor Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 A
Notes
a. Device mounted with all leads soldered or welded to PC board.
b. Derate 7.4 mW/_C above 85_C.
c. Derate 14 mW/_C above 85_C.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation
of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING RANGE
V_IN Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 V to 5.5 V
C_IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mF Ceramic
C_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 mF Ceramic
Inductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 mH
Operating Load Current PWM Mode . . . . . . . . . . . . . . . . . . . . . . 0 to 600 mA
Operating Load Current PSM Mode . . . . . . . . . . . . . . . . . . . . . . . 0 to 150 mA
SPECIFICATIONS
Parameter
Mode^f Symbol
Under Voltage Lockout (UVLO)
Under Voltage Lockout (turn-on)
Hysteresis
Test Conditions Unless Specified
−40_C to 85_C, V_IN = V_DD, V_DAC = 1.215 V, C_IN = 10 mF,
C_OUT = 4.7 mF, L = 2.2 mH, 2.6 V v V_IN v 5.5 V
R₁ = 11.3 kW, R₂ = 20 kW
V_IN rising
Shutdown (SD)
Logic HIGH
Logic LOW
V_SDH
V_SDL
Delay to Output^c
Pull Down
t_en
Settle Within $2% accuracy SD rising
t_r < 1 ms
I_SD
Input at V_IN
Mode Selection Tri-Level Logic (MODE)
MODE Pin HIGH
MODE Pin LOW
Mode Pin Input Current
PWM
Auto
MODE = GND
MODE = V_IN
Oscillator
Frequency
f_OSC
External Clock Synchronization (SYNC)
R_L = 3.3 W
R_L = 51 W
Frequency
Ac Coupled Sinewave
SYNC Input = 500 mV_p-p
Frequency = 13 MHz
Error Amplifier (FB, DAC Pin)
FB Voltage Accuracy
DAC Input Voltage Range
Input Bias Current FB, DAC
I_FBDAC
V_IN > 2.6, V_{IN −} V_DAC > 0.5 V
V_FB = 1.25 V
Limits
Min^a Typ^b Max^a
2.3
2.5
0.1
1.6
0.4
100
100
V_IN −0.4
V_IN
0.4
−5
5
1.6
2
2.4
13
0.2
0.8
V_DAC
−20
0.28
−1
0.01
V_DAC
+20
2.45
1
Unit
V
V
ms
mA
V
mA
MHz
MHz
V_p-p
mV
V
mA
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Document Number: 71668
S-41148—Rev. C, 14-jun-04