參數資料
型號: LM2792LD-H
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 顯示驅動器
英文描述: Current Regulated Switched Capacitor LED Driver with Analog Brightness Control
中文描述: LED DISPLAY DRIVER, DSO10
封裝: 3 X 3 MM, 0.80 MM HEIGHT, LLP-10
文件頁數: 7/10頁
文件大?。?/td> 204K
代理商: LM2792LD-H
Circuit Description
The LM2792 provides two matched current sources for driv-
ing high forward voltage drop LEDs from Li-Ion battery
sources. The part has on-chip current regulators which are
composed of current mirrors with a 25 to 1 ratio. The mirrors
control the LED current without using current limiting resis-
tors in the LED current path. The device can drive up to
34mA through the Leds.
The LED brightness can be controlled by both analog and/or
digital methods. The digital technique uses a PWM (Pulse
Width Modulation) signal applied to the shutdown input. The
analog technique applies an analog voltage to the brightness
(BRGT) pin (see Application Information section).
Application Information
SOFT START
LM2792 includes a soft start function to reduce the inrush
currents and high peak current during power up of the de-
vice. Soft start is implemented internally by ramping the
bandgap more slowly than the applied voltage. This is done
by holding the bandgap in shutdown for a short time. During
soft start, the switch resistances limit the inrush current used
to charge the flying and hold capacitors.
SHUTDOWN MODE
A shutdown pin (SD or SD) is available to disable the
LM2792 and reduce the quiescent current to 1μA maximum.
The LM2792 is available with both senses of shutdown
polarity.
During normal operation mode of the ’-L’ options, an active
high logic signal to the SD pin or tying the SD pin to V
, will
enable the device. Pulling SD low or connecting SD to
ground will disable the device.
During normal operation mode of the ’-H’ options, an active
low logic signal to the SD pin or tying the SD pin to GND, will
enable the device. Pulling SD high or connecting SD to V
IN
will disable the device.
CAPACITOR SELECTION
Low equivalent series resistance (ESR) capacitors such as
X5R or X7R are recommended to be used for C
, C1, and
C
for best performance. Ceramic capacitors with less
than or equal to 0.3 ohms ESR value are recommended for
this application.
Table 1
below lists suggested capacitor
suppliers for the typical application circuit.
TABLE 1. Low ESR Capacitor Manufactures
Manufacturer
TDK
MuRata
Taiyo Yuden
Contact
(847) 803 6100
(800) 831 9172
(800) 348 2496
website
www.component.tdk.com
www.murata.com
www.t-yuden.com
SCHOTTKY DIODE SELECTION
A schottky diode (SD1) must be used between V
and P
for proper operation. During start-up, the low voltage drop
across this diode is used to charge C
and start the
oscillator. It is necessary to protect the device from
turning-on its own parasitic diode and potentially latching-up.
As a result, it is important to select a schottky diode that will
carry at least 200mA or higher current to charge the output
capacitor during start-up. A schottky diode like 1N5817 can
20024204
FIGURE 1.
L
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相關PDF資料
PDF描述
LM2792 Current Regulated Switched Capacitor LED Driver with Analog Brightness Control
LM2792LD-L Silver Mica Capacitor; Capacitance:5100pF; Capacitance Tolerance:+/- 5%; Series:CDV30; Voltage Rating:1000VDC; Capacitor Dielectric Material:Mica; Termination:Radial Leaded; Lead Pitch:11.1mm; Leaded Process Compatible:No RoHS Compliant: No
LM2792LDX-H Silver Mica Capacitor; Capacitance:6800pF; Capacitance Tolerance:+/- 5%; Series:CDV30; Voltage Rating:1500VDC; Capacitor Dielectric Material:Mica; Termination:Radial Leaded; Lead Pitch:11.1mm; Leaded Process Compatible:No RoHS Compliant: No
LM2792LDX-L Silver Mica Capacitor; Capacitance:7500pF; Capacitance Tolerance:+/- 5%; Series:CDV30; Voltage Rating:1500VDC; Capacitor Dielectric Material:Mica; Termination:Radial Leaded; Lead Pitch:11.1mm; Leaded Process Compatible:No RoHS Compliant: No
LM27953TLX CABLE 64 COND 100FT TWISTED PAIR
相關代理商/技術參數
參數描述
LM2792LD-H/NOPB 功能描述:IC LED DRIVR WHITE BCKLGT 10-LLP RoHS:是 類別:集成電路 (IC) >> PMIC - LED 驅動器 系列:- 標準包裝:1 系列:- 恒定電流:- 恒定電壓:- 拓撲:PWM,切換式電容器(充電泵) 輸出數:1 內部驅動器:是 類型 - 主要:背光 類型 - 次要:白色 LED 頻率:642kHz 電源電壓:2.7 V ~ 5.5 V 輸出電壓:5V 安裝類型:表面貼裝 封裝/外殼:10-VFDFN 裸露焊盤 供應商設備封裝:10-VSON 包裝:剪切帶 (CT) 工作溫度:-30°C ~ 85°C 產品目錄頁面:1371 (CN2011-ZH PDF) 其它名稱:BD1603NUV-E2CT
LM2792LD-L 制造商:Rochester Electronics LLC 功能描述: 制造商:Texas Instruments 功能描述:
LM2792LD-L/NOPB 功能描述:IC LED DRIVR WHITE BCKLGT 10-LLP RoHS:是 類別:集成電路 (IC) >> PMIC - LED 驅動器 系列:- 標準包裝:1 系列:- 恒定電流:- 恒定電壓:- 拓撲:PWM,切換式電容器(充電泵) 輸出數:1 內部驅動器:是 類型 - 主要:背光 類型 - 次要:白色 LED 頻率:642kHz 電源電壓:2.7 V ~ 5.5 V 輸出電壓:5V 安裝類型:表面貼裝 封裝/外殼:10-VFDFN 裸露焊盤 供應商設備封裝:10-VSON 包裝:剪切帶 (CT) 工作溫度:-30°C ~ 85°C 產品目錄頁面:1371 (CN2011-ZH PDF) 其它名稱:BD1603NUV-E2CT
LM2792LDX-H 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Current Regulated Switched Capacitor LED Driver with Analog Brightness Control
LM2792LDX-L 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Current Regulated Switched Capacitor LED Driver with Analog Brightness Control