S-8540A15FN-IAAT2Z Datasheet, PDF (8/36 Pages) Seiko Instruments Inc – SWITCHABLE SWITCHING REGULATOR CONTROLLER

STEP-DOWN, 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8540/8541 Series
Rev.4.0_01
2. S-8540/8541 Series B, D types
Table 6
(Ta = 25 °C,unless otherwise specified)
Parameter
Symbol
Conditions
Measure-
Min.
Typ.
Max.
Units ment
Circuit
Output voltage ^{*1, *2}
VOUT (E)
VIN = 4.5 V
IOUT = 120 mA
VOUT (S)
× 0.980
VOUT (S)
= 3.000
VOUT (S)
× 1.020
V
4
Input voltage
VIN
−
2.5
−
10.0
V
3
Current consumption 1
ISS1
VIN = 4.5 V
100% duty ratio
S-8540/8541B00
S-8540/8541D00
−
−
180
140
300
240
μA
3
Current consumption
during shutdown
ISSS
VON/OFF = 0 V
VOUT = VOUT (S) × 0.95
−
−
1.0
μA
3
EXT pin output current
IEXTH
VIN = 10 V, VEXT = VIN − 0.2 V
IEXTL
VIN = 10 V, VEXT = 0.2 V
− 32
− 48
−
mA
3
45
66
−
mA
3
Line regulation
ΔVOUT1
3.3 ≤ VIN ≤ 10 V, IOUT = 120 mA
−
30
60
mV
4
Load regulation
ΔVOUT2
10 μA ≤ IOUT ≤ 150 mA
−
30
60
mV
4
Output voltage
temperature coefficient
ΔV_OUT
ΔTa • V_OUT
VIN = VOUT (S) × 1.5, IOUT = 120 mA
− 40 ≤ Ta ≤ + 85°C
−
± 100
−
ppm/
°C
4
Oscillation frequency
fOSC
Measure waveform at
the EXT pin.
S-8540/8541B00
S-8540/8541D00
510
255
600
300
690
345
kHz
4
Maximum duty ratio
MaxDuty Measure waveform at the EXT pin.
100
−
−
%
4
PWM/PFM-control switch
duty ratio ^*3
PFM Duty VIN = VOUT (S) × 1.5 V, no load
19
29
39
%
4
Current limit detection
voltage
VSENSE VIN = 4.5 V, Measure waveform at the EXT pin.
100
125
150
mV
3
SENSE pin input current
ISENSE
VIN = 4.5 V, VSENSE = VIN − 0.1 V
6.7
11.2
16.8
μA
3
Shutdown pin
input voltage
VSH
VIN = 4.5 V, Judge VOUT (S) × 0.98.
VSL
VIN = 4.5 V, Judge CVREF pin "L".
2.3
−
−
V
4
−
−
0.3
V
3
Shutdown pin
ISH
VIN = 4.5 V, VON/OFF = VOUT
− 0.1
−
0.1
μA
3
input leakage current
ISL
VIN = 4.5 V, VON/OFF = 0 V
− 0.1
−
0.1
μA
3
Soft-start time
tSS
Time until VOUT (E) reaches 90% or higher of the
VOUT (S)
7.0
12.0
17.0
ms
4
Efficiency
EFFI
−
−
90
−
%
4
External components:
Coil (L)
:Sumida Corporation CDRH6D28-100
Diode (SD)
:Matsushita Electric Inducstrial Co., Ltd. MA2Q737 (Schottky diode)
Output capacitor (COUT) :Nichicon Corporation F93 (16 V, 47 μF, tantalum)
Input capacitor (CIN)
Transistor (PSW)
:Nichicon Corporation F93 (16 V, 47 μF, tantalum)
:Toshiba Corporation 2SA1213
Base resistor (Rb)
Base capacitor (Cb)
:100 mΩ
:2200 pF
CVL
:1.0 μF
CSS
:0.047 μF
RSS
:220 kΩ
RSENSE
:100 mΩ
RA
:200 kΩ
RB
:100 kΩ
CFB
:50 pF
Condition: Connect recommended parts unless otherwise specified. VIN =4.5 V, IOUT =120 mA
*1. VOUT (S) : Specified output voltage value, VOUT (E) : Actual output voltage value
*2. The typical value (specified output voltage value) is VOUT (S) = 1 + RA/RB = 3.0 V. See “Output Voltage adjustment”.
*3. S-8541 series only
Caution 1. Line regulation and load regulation may change greatly due to GND wiring when VIN is high.
2. In the S-8540 series (PWM control), a state in which the duty ratio 0% continues for several
clocks may occur when the input voltage is high and the output current is low. In this case,
the operation changes to the pseudo PFM mode, but the ripple voltage hardly increases.
8