S-8340A30AFT-T2-G Seiko Instruments, S-8340A30AFT-T2-G Datasheet - Page 18

• Manufacturer Part Number: S-8340A30AFT-T2-G
• Description: IC REG SW 600KHZ 3.0V 8-TSSOP
• Manufacturer: Seiko Instruments
• Type: Step-Up (Boost)r

Specifications of S-8340A30AFT-T2-G

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3V
• Frequency - Switching: 600kHz
• Voltage - Input: 0.9 ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP
• Power - Output: 300mW
• Output Voltage: 3 V
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

18
STEP-UP, 600 kHz, PWM CONTROL OR PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8340/8341 Series
Figure 11 ON/OFF Pin Structure
3. ON/OFF Pin (Shutdown Pin)
ON/OFF
The soft-start circuit of the S-8340/8341 Series increases the duty ratio gradually as shown in Figure 10.
The soft-start time (t
If f
If V
Even if the IC reaches a certain duty at a duty ratio of 0 to 43%, there may be a delay of the output voltage (V
reaching the specified voltage (V
in reaching the specified voltage (1.0 V). Note that the maximum delay time may be the value calculated when a
duty ratio is 43%.
The ON/OFF pin stops or starts the step-up operation.
When the ON/OFF pin is set to "L", all the internal circuits stop operating, reducing power consumption. The EXT
pin voltage becomes equal to the V
The ON/OFF pin is configured as shown in Figure 11 and is not either pulled up or pulled down. So, do not use it
in a floating state. Applying 0.3 to 0.8 V to the ON/OFF pin increases current consumption. So do not apply such
voltage. When the ON/OFF pin is not used, connect it to the VDD pin. The ON/OFF pin does not have hysterisis.
OSC
IN
≥ 2 V, the approximate time until a specific duty ratio is reached is calculated from the following formula :
= 600 kHz and C
VSS
VDD
If f
If f
OSC
OSC
SS
) can be set with an external capacitor (C
= 600 kHz, t
= 300 kHz, t
SS
= 4700 pF, the time until the duty ratio of 50% is reached is 9.7 ms (typ.).
Figure 10 Image of EXT Pin Waveform
OUT(S)
SS
SS
SS
[ms] = C
[ms] = C
voltage, thereby turning off the switching transistor.
). This delay occurs due to the delay of the error amplifier reference voltage
*1. Voltage obtained by extracting the voltage drop due to DC
ON/OFF Pin
resistance of the inductor and the diode forward voltage from V
Seiko Instruments Inc.
“H”
“L”
SS
SS
[pF] ×
[pF] ×
8.336 × Duty [%] + 682.45
6.564 × Duty [%] + 698
CR Oscillation Circuit
SS
Operating
Stopped
).
535000
229000
Output Voltage
Set value
≅V
IN
*1
Rev.4.0
IN
.
OUT
_00
) in