XC9133B02AMR-G Torex Semiconductor Ltd, XC9133B02AMR-G Datasheet - Page 7

• Manufacturer Part Number: XC9133B02AMR-G
• Description: IC BOOST ADJ .26A SOT25-5
• Manufacturer: Torex Semiconductor Ltd
• Type: Step-Up (Boost)r

Specifications of XC9133B02AMR-G

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 2.5 ~ 17.5 V
• Current - Output: 260mA
• Frequency - Switching: 1MHz
• Voltage - Input: 2.5 ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Power - Output: 250mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

■APPLICATION INFORMATION
<Dimming Control>
1. Applying PWM signal to the CE pin
2. Step-Wise Regulation of LED Current
The XC9133 repeats on/off operations by a PWM signal applied to the CE pin. The magnitude of LED current, I
when the diode is on, is determined by R
is proportional to the positive duty ratio of the PWM signal.
The frequency of the PWM signal can be controlled to the optimum value between 100Hz and 10kHz. With regard to the
amplitude of the PWM signal, the high level should be higher than the "H" voltage of CE, V
than the "L" voltage of CE, V
In some applications, it may be necessary to incorporate step-wise regulation of LED current, I
of LED illumination is achieved by connecting a switch element SW1 in parallel with R
turning SW1 on and off, as shown below. Choose a resistance of R
when switch element SW1 is off. The resistance of R
through the LED is gained when the switch element is on.
Ex.) Current I
R
R
LED
LED1
10kHz, 3 series LED, I
1kHz, 3 series LED, I
= 200mV / 5mA = 40
= 200mV / (15mA – 5mA) = 20
LED
200μs / div
20μs / div
= 5mA and 15mA
CEL
.
LED
LED
=20mA
Ω
=20mA
LED
. The magnitude is zero when the diode is off. The average of LED current
Ω
LED1
Figure
should be such that a desired increase of current passed
Circuit using Step-wise Regulation of LED Current
LED
so that the minimum necessary current is gained
1kHz, 4 series LED, I
10kHz, 4 series LED, I
LED
200μs / div
20μs / div
and in series with R
CEH
LED
, and the low level, lower
. Step-wise regulation
LED
LED
=20mA
=20mA
XC9133
Series
LED1
7/15
LED
and
,