參數(shù)資料
型號(hào): LTC1438XCG
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: Dual High Efficiency, Low Noise, Synchronous Step-Down Switching Regulators
中文描述: 2 A DUAL SWITCHING CONTROLLER, 400 kHz SWITCHING FREQ-MAX, PDSO28
封裝: 0.209 INCH, PLASTIC, SSOP-28
文件頁(yè)數(shù): 23/32頁(yè)
文件大?。?/td> 596K
代理商: LTC1438XCG
23
LTC1438/LTC1439
APPLICATIO
S I
N
FOR
ATIO
U
W
U
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
RUN/SS1
SENSE
+
1
SENSE
1
V
PROG1
I
TH1
POR2
C
OSC
SGND
LBI
LBO
SFB1
I
TH2
V
PROG2
V
OSENSE2
SENSE
2
SENSE
+
2
RUN/SS2
AUXDR
PLL LPF
PLLIN
BOOST 1
TGL1
SW1
TGS1
V
IN
BG1
INTV
CC
PGND
BG2
EXTV
CC
TGS2
SW2
TGL2
BOOST 2
AUXON
AUXFB
LTC1439
D
B1
D
B2
M3
M1
C
IN1
C
IN2
C
OUT1
+
C
OUT2
R
SENSE1
R
SENSE2
C
B1
0.1
μ
F
C
LP
0.01
μ
F
C
1000pF
R
10k
EXT
CLOCK
C
B2
0.1
μ
F
M2
D1
L1
L2
GROUND PLANE
D2
M5
1438 F13
M6
M4
4.7
μ
F
+
+
+
+
+
R
C1
10k
R
10k
+
V
OUT1
+
V
IN
V
OUT2
1000pF
1000pF
220pF
NOT ALL PINS CONNECTED FOR CLARITY
BOLD LINES INDICATE HIGH CURRENT PATHS
INTV
CC
INTV
CC
V
IN
100k
1000pF
C
OSC
C
220pF
C
SS
0.1
μ
F
C
470pF
C
1000pF
C
SS
0.1
μ
F
OUTPUT DIVIDER
REQUIRED WITH
V
PROG
OPEN
100pF
22pF
10
10
Figure 13. LTC1439 Physical Layout Diagram
PC Board Layout Checklist
When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC1438/LTC1439. These items are also illustrated graphi-
cally in the layout diagram of Figure 13. Check the follow-
ing in your layout:
1. Are the high current power ground current paths using
or running through any part of signal ground The
LTC1438/LTC1438X/LTC1439 ICs have their sensitive
pins on one side of the package. These pins include the
signal ground for the reference, the oscillator input, the
voltage and current sensing for both controllers and the
low-battery/comparator input. The signal ground area
used on this side of the IC must return to the bottom
plates of all of the output capacitors. The high current
power loops formed by the input capacitors and the
ground returns to the sources of the bottom N-channel
MOSFETs, anodes of the Schottky diodes and (–) plates
of C
IN
, should be as short as possible and tied through
a low resistance path to the bottom plates of the output
capacitors for the ground return.
2. Do the LTC1438/LTC1439 SENSE
1 and V
OSENSE2
pins
connect to the (+) plates of C
OUT
In adjustable applica-
tions, the resistive divider R1/R2 must be connected
between the (+) plate of C
OUT
and signal ground and the
HF decoupling capacitor should be as close as possible
to the LTC1438/LTC1439.
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LTC1438XCG#TR 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1438XCG#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
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