S-8520A20MC-AVFT2X Datasheet, PDF (10/44 Pages) Seiko Instruments Inc – SWITCHING REGULATOR CONTROLLER

STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8520/8521 Series
Rev.9.0_01
2. C type, D type
Table 6
(Ta = +25°C unless otherwise specified)
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Test
Circuit
Output voltage^*1
VOUT(E)
−
VOUT(S)
× 0.976
VOUT(S)
VOUT(S)
× 1.024
V
3
Input voltage
VIN
C type
−
D type
2.5
−
10.0 V
2
2.5
−
16.0 V
2
Current consumption 1 ISS1
Current consumption
during shutdown
ISSS
VOUT = VOUT(S) × 1.2
V = 0 V ^______
ON/OFF
−
10
21 μA 2
−
−
0.5 μA 2
S-8520/8521x15 to 24 −2.3 −4.5
− mA −
S-8520/8521x25 to 34 −3.7 −7.0
− mA −
IEXTH
VEXT = VIN − 0.4 V S-8520/8521x35 to 44 −5.3
S-8520/8521x45 to 54 −6.7
−9.3
−11.3
− mA −
− mA −
EXT pin output current
S-8520/8521x55 to 60 −8.0
S-8520/8521x15 to 24 +4.3
−13.3
+8.4
− mA −
− mA −
S-8520/8521x25 to 34 +7.0 +13.2
− mA −
IEXTL
VEXT = 0.4 V
S-8520/8521x35 to 44 +9.9 +17.5
S-8520/8521x45 to 54 +12.6 +21.4
− mA −
− mA −
S-8520/8521x55 to 60 +15.0 +25.1
− mA −
Line regulation
Load regulation
Output voltage
temperature coefficient
ΔVOUT1
ΔVOUT2
ΔVOUT
ΔTa
VOUT(S) ≤ 2.0 V VIN = 2.5 V to 2.94 V
VOUT(S) > 2.0 V VIN = VOUT(S) × 1.2 to 1.4
Load current = 10 μA to IOUT × 1.25
Ta = −40°C to +85°C
−
30
60 mV 3
−
30
60 mV 3
−
30
60 mV 3
−
±VOUT(S)
× 5E − 5
−
V/°C
3
Oscillation frequency
fosc
PWM / PFM control
Measure waveform at
VOUT(S) ≤ 2.4 V 45
60
75 kHz 3
EXT pin.
VOUT(S) ≥ 2.5 V 48
60
72 kHz 3
switching duty ratio
PFMDuty No load, measured waveform at EXT pin. 15
25
40
%
3
(S-8521 Series)
ON/OFF pin
VSH
Determine oscillation at EXT pin
1.8
−
−
V
2
input voltage
ON/OFF pin
VSL
Determine oscillation stop at EXT pin
−
−
0.3 V
2
ISH
−
−0.1
−
0.1 μA 1
input leakage current
ISL
−
−0.1
−
0.1 μA 1
Soft start time
Overload detection time
(C type)
Efficiency
tss
tpro
EFFI
−
6.0
Time until the EXT pin reaches VIN after
dropping VOUT to 0 V.
7.0
−
−
12.0 24.0 ms 3
14.0 28.0 ms 2
93
−
%
3
External parts Coil:
Sumida Corporation CD54 (47 μH)
Diode:
Matsushita Electric Industrial Co., Ltd. MA720 (Shottky type)
Capacitor:
Matsushita Electric Industrial Co., Ltd. TE (16 V, 22 μF tantalum type)
Transistor:
Toshiba Corporation 2SA1213
Base resistance (Rb): 0.68 kΩ
Base capacitor (Cb): 2200 pF (Ceramic type)
Unless otherwise indicated, connect the recommended components to the IC. When VIN = VOUT(S) × 1.2 V (VIN = 2.5 V
______
when VOUT(S) ≤ 2.0 V), IOUT = 120 mA, connect the ON/OFF pin to the VIN pin.
*1. VOUT(S): Specified output voltage value, VOUT(E): Actual output voltage value
10