参数资料
型号: LTC6992CDCB6-2#PBF
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: SWITCHING CONTROLLER, PDSO6
封装: 2 X 3 MM, LEAD FREE, PLASTIC, MO-229TBD, DFN-6
文件页数: 6/32页
文件大小: 322K
代理商: LTC6992CDCB6-2#PBF
LTC6992-1/LTC6992-2/
LTC6992-3/LTC6992-4
14
69921234p
OPERATION
The LTC6992 is built around a master oscillator with a
1MHz maximum frequency. The oscillator is controlled
by the SET pin current (ISET) and voltage (VSET), with a
1MHz 50k conversion factor that is accurate to ±0.8%
under typical conditions.
fMASTER =
1
tMASTER
= 1MHz 50k
ISET
VSET
A feedback loop maintains VSET at 1V ±30mV, leaving ISET
as the primary means of controlling the output frequency.
The simplest way to generate ISET is to connect a resistor
(RSET) between SET and GND, such that ISET = VSET/RSET.
The master oscillator equation reduces to:
fMASTER =
1
tMASTER
=
1MHz 50k
RSET
From this equation it is clear that VSET drift will not affect
the output frequency when using a single program resistor
(RSET). Error sources are limited to RSET tolerance and the
inherent frequency accuracy
ΔfOUT of the LTC6992.
RSET may range from 50k to 800k (equivalent to ISET
between 1.25μA and 20μA).
The LTC6992 includes a programmable frequency divider
which can further divide the frequency by 1, 4, 16, 64,
256, 1024, 4096 or 16384 before driving the OUT pin.
The divider ratio NDIV is set by a resistor divider attached
to the DIV pin.
fOUT =
1
tOUT
=
1MHz 50k
NDIV
ISET
VSET
With RSET in place of VSET/ISET the equation reduces to:
fOUT =
1
tOUT
=
1MHz 50k
NDIV RSET
DIVCODE
The DIV pin connects to an internal, V+ referenced 4-bit
A/D converter that monitors the DIV pin voltage (VDIV) to
determine the DIVCODE value. DIVCODE programs two
settings on the LTC6992:
1. DIVCODE determines the output frequency divider
setting, NDIV.
2. DIVCODE determines the output polarity, via the POL
bit.
VDIV may be generated by a resistor divider between V+
and GND as shown in Figure 1.
Figure 1. Simple Technique for Setting DIVCODE
6992 F01
LTC6992
V+
DIV
GND
R1
R2
2.25V TO 5.5V
相关PDF资料
PDF描述
LM2675-3.3MWC 2.2 A SWITCHING REGULATOR, 275 kHz SWITCHING FREQ-MAX, UUC
LM4051BIX3-1.2+T 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.225 V, PDSO3
LT1840-7DZB1 1-OUTPUT AC-DC REG PWR SUPPLY MODULE
LTC3873ITS8-5#PBF SWITCHING CONTROLLER, PDSO8
LES40A48-2V5RA 1-OUTPUT 100 W DC-DC REG PWR SUPPLY MODULE
相关代理商/技术参数
参数描述
LTC6992CDCB6-2-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)
LTC6992CDCB6-3-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)
LTC6992CDCB6-3-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)
LTC6992CDCB6-4-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)
LTC6992CDCB6-4-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)