S-8333CAAA-I8T1U Datasheet, PDF (7/44 Pages) Seiko Instruments Inc – PWM CONTROL SWITCHING REGULATOR CONTROLLER

STEP-UP, FOR LCD BIAS SUPPLY, 1-CHANNEL, PWM CONTROL SWITCHING REGULATOR CONTROLLER
Rev.4.2_01
S-8333 Series
 Electrical Characteristics
Table 4 Electrical Characteristics
(Unless otherwise specified: VIN = 3.3 V, Ta = 25°C)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Test
Circuit
Operating input voltage VIN
FB voltage
VFB
Current consumption ISS1
EXT pin output current
IEXTH
IEXTL
FB voltage temperature ΔVFB
coefficient
ΔTa
FB pin input current IFB
Oscillation frequency^*1 fosc
⎯
⎯
fosc = 650 kHz
VFB = 0.95 V
VEXT = VIN − 0.4 V
VEXT = 0.4 V
1.8
⎯
6.0
V
2
0.985 1.000 1.015
V
2
⎯
450
700
μA
1
⎯
−100
−60
mA
1
100
160
⎯
mA
1
Ta = −40 to +85°C
⎯
±100
⎯ ppm/°C 2
⎯
−0.1
⎯
+0.1
μA
1
When fosc = 1080 kHz is set
(ROSC = 120 kΩ)
When fosc = 650 kHz is set
(ROSC = 200 kΩ)
When fosc = 280 kHz is set
fosc
× 0.9
fosc
fosc
× 1.1
kHz
1
(ROSC = 470 kΩ)
VFB = 0.9 V
Waveform on EXT pin is measured.
Oscillation frequency Δfosc
temperature coefficient ΔTa
Ta = −40 to +85°C
fosc = 650 kHz
⎯
1000
⎯ ppm/°C 1
fosc = 1080 kHz (ROSC = 120 kΩ)
MaxDuty = 88.5% (RDuty = 62 kΩ)
Max. duty^*2
MaxDuty
MaxDuty = 73% (RDuty = 180 kΩ)
MaxDuty = 47% (RDuty = 390 kΩ)
MaxDuty
−5
MaxDuty
MaxDuty
+5
%
1
fosc = 650 kHz (ROSC = 200 kΩ)
MaxDuty = 88.5% (RDuty = 100 kΩ)
Soft-start time
tSS
tSS = 10 ms, 15 ms, 20 ms
Selected in three steps
tSS
× 0.75
tSS
tSS
× 1.5
ms
1
Short-circuit protection
delay time^*3
tPRO
tPRO = 50 ms
(CSP = 0.1 μF)
37.5
50
75
ms
1
UVLO detection voltage VUVLO
VUVLO = 1.5 V to 2.3 V
Selected in 0.1 V steps
VUVLO
× 0.95
VUVLO
VUVLO
× 1.05
V
1
UVLO hysteresis width VUVLOHYS
VUVLOHYS = 0.1 V to 0.3 V
Selected in 0.1 V steps
VUVLOHYS
× 0.6
VUVLOHYS
VUVLOHYS
× 1.4
V
1
CC pin output current
ICCH
ICCL
VFB = 2 V
VFB = 0 V
−60
−45 −34.5
μA
1
34.5
45
60
μA
1
VRTLT1
Timer latch reset voltage
VRTLT2
Within short-circuit protection delay
time
After short-circuit protection circuit
operated
0.7
VUVLO
× 0.95
1.0
VUVLO
1.3
VUVLO
× 1.05
V
V
1
1
*1. The recommended range of the resistance (Rosc) for oscillation frequency is Rosc = 120 kΩ to 470 kΩ (fOSC = 280 kHz to 1.08 MHz).
This range of oscillation frequency is the typical value when an ideal resistor is connected externally. In actual use, it is necessary to
take account the dispersion of an IC (±10%) into this value.
*2. Set max. duty; Between 47 and 88.5 % (RDuty/ROSC = 0.5 to 3.2); the oscillation frequency is 500 kHz or more
Between 47 and 80 % (RDuty/ROSC = 1.0 to 3.2); the oscillation frequency is less than 500 kHz
This range of max. duty is the typical value when an ideal resistor is connected externally. In actual use, it is necessary to take
account the dispersion of an IC (±5%) into this value.
*3. The short-circuit protection time can be set by the external capacitor. Although the maximum set value by the external capacitor is
unlimited under the ideal condition, set CSP = approx. 0.47 μF as a target maximum value due to discharge time of the capacitor.
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