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參數資料
| 型號： | LTC1923EUH |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | High Efficiency Thermoelectric Cooler Controller |
| 中文描述： | SWITCHING CONTROLLER, 270 kHz SWITCHING FREQ-MAX, PQCC32 |
| 封裝： | 5 X 5 MM, PLASTIC, QFN-32 |
| 文件頁數： | 15/28頁 |
| 文件大?。?/td> | 452K |
| 代理商： | LTC1923EUH |
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15
LTC1923
1923f
The terms containing the fixed resistance values are the
loading errors introduced by the input impedance of the
differential amplifier. A common mode voltage error is
also introduced since the addition of R
TE1
and R
TE2
change
the fully differential nature of the amplifier. In order to
minimize these errors select R
TE1
and R
TE2
to be 10k or
less. The above equation reduces to:
V
R
R
TECOOLER
TE
TE
+
1
2 5
.
1
2
The Higher Voltage Applications section shows a fully
differential means to increase the clamp voltage.
This will similarly alter the heating and cooling direction
thresholds by the same factor, increasing the thresholds
to
(R
TE1
and R
TE2
are assumed to be
≤
10k)
:
DIRH
mV
R
R
DIRL
mV
R
R
TE
TE
TE
TE
=
+
=
+
50
1
50
1
1
2
1
2
–
The output voltage on the VTEC pin, V
VTEC
, will be reduced
by the same ratio:
V
V
R
R
VTEC
TECOOLER
+
1
TE
TE
=
1
2
Oscillator Frequency
The oscillator determines the switching frequency and the
fundamental positioning of all harmonics. The switching
frequency also affects the size of the inductor that needs
to be selected for a given inductor ripple current (as
opposed to TEC ripple current which is a function of both
the filter inductor and capacitor). A higher switching
frequency allows a smaller valued inductor for a given
ripple current. The oscillator is a triangle wave design. A
current defined by external resistor R
T
is used to charge
and discharge the capacitor C
T
. The charge and discharge
rates are equal. The selection of high quality external
components (5% or better multilayer NPO or X7R ceramic
capacitor) is important to ensure oscillator frequency
stability.
The frequency of oscillation is determined by:
f
OSC(kHz)
= 750 10
6
/[R
T
(k
) C
T
(pF)]
The LTC1923 can run at frequencies up to 1MHz. The value
selected for R
T
will also affect the delay time between one
side of the full bridge turning off and the opposite side
turning on. This time is also known as the “break-before-
make” time. The typical value of 10k
will produce a 90ns
“break-before-make” time. For higher frequency applica-
tions, a smaller value of R
T
may be required to reduce this
delay time. For applications where significant slew rate
limiting or external gate driver chips are used, a higher
value for R
T
may necessary, increasing the dead time. The
“break-before-make” time can be approximately calcu-
lated by:
t
DELAY
= R
T
(k
) 5.75 10
–9
+ 35ns
Phase-Locked Loop
The LTC1923 has an internal voltage-controlled oscillator
(VCO) and phase detector comprising a phase-locked
loop. This allows the oscillator to be synchronized with
another oscillator by slaving it to a master through the
SDSYNC pin. The part can also be designated as the
master by pulling the PLLLPF pin high to V
DD
. This will
result in the part toggling the SDSYNC pin at its set
oscillator frequency. This signal can then be used to
synchronize additional oscillators.
When being slaved to another oscillator, the frequency
should be set 20% to 30% lower than the target frequency.
The frequency lock range is approximately
±
50%.
The phase detector is an edge sensitive digital type, which
provides zero degrees phase shift between the external
and internal oscillators. This detector will not lock up on
input frequencies close to the harmonics of the VCO center
frequency. The VCO hold-in range is equal to the capture
range dfH = dfC =
±
0.5f
O
.
The output of the phase detector is a complementary pair
of current sources charging or discharging the external
filter network on the PLLLPF pin. A simplified block
diagram is shown in Figure 8.
OPERATIOU
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相關代理商/技術參數 |
參數描述 |
|---|---|
| LTC1923EUH#PBF | 功能描述:IC THERMOELEC COOLER CNTRLR32QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:50 系列:- 應用:熱電冷卻器 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC（0.173"，4.40mm 寬）裸露焊盤 供應商設備封裝:28-TSSOP 裸露焊盤 包裝:管件 產品目錄頁面:1410 (CN2011-ZH PDF) |
| LTC1923EUH#TR | 功能描述:IC THERMOELEC COLLER CNTRLR32QFN RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標準包裝:1 系列:- 應用:手持/移動設備 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應商設備封裝:14-LLP-EP（4x4） 包裝:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名稱:LP3905SD-30DKR |
| LTC1923EUH#TRPBF | 功能描述:IC THERMOELEC COOLER CNTRLR32QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標準包裝:1 系列:- 應用:手持/移動設備 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應商設備封裝:14-LLP-EP（4x4） 包裝:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名稱:LP3905SD-30DKR |
| LTC1928ES6-5#PBF | 制造商:Linear Technology 功能描述:Charge Pump STPUP 5V 30mA 6-Pin TSOT-23 |
| LTC1928ES6-5#TR | 功能描述:IC REG SWITCHED CAP DBL SOT23-6 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 標準包裝:500 系列:- 類型:切換式電容器（充電泵），反相 輸出類型:固定 輸出數:1 輸出電壓:-3V 輸入電壓:2.3 V ~ 5.5 V PWM 型:Burst Mode? 頻率 - 開關:900kHz 電流 - 輸出:100mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 細型，TSOT-23-6 包裝:帶卷 (TR) 供應商設備封裝:TSOT-23-6 其它名稱:LTC1983ES6-3#TRMTR |
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