- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377765 > LTC1923 (Linear Technology Corporation) High Efficiency Thermoelectric Cooler Controller PDF資料下載
參數(shù)資料
| 型號： | LTC1923 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | High Efficiency Thermoelectric Cooler Controller |
| 中文描述： | 高效熱電制冷控制器 |
| 文件頁數(shù)： | 12/28頁 |
| 文件大?。?/td> | 452K |
| 代理商： | LTC1923 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁當(dāng)前第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
12
LTC1923
1923f
PROTECTION FEATURES
Many protection features have been integrated into the
LTC1923 to ensure that the TEC is not overstressed or the
system does not thermally run away. These features
include pulse-by-pulse current limiting, TEC voltage clamp-
ing and open/shorted thermistor detection.
Current Limit
The peak current in the full bridge during each switching
cycle can be limited by placing a sense resistor, R
S
, from
the common NMOS source connections of MNA and MNB
to ground. The CS
+
and CS
–
connections should be made
as shown in Figure 1. Current limit is comprised of a fixed
gain of ten differential amplifier, an attenuator (resistor
divider) and a current limit comparator. A detailed diagram
of the circuitry is shown in Figure 3. The differential
amplifier output, I
TEC
, is provided to allow the user the
ability to monitor the instantaneous current flowing in the
bridge. If an average current is desired, an external RC
filter can be used to filter the I
TEC
output. Approximately
50ns of leading edge blanking is also internally integrated
to prevent nuisance tripping of the current sense circuitry.
It relieves the filtering requirements for the CS input pins.
During a switching cycle, current limit occurs when the
voltage on I
TEC
exceeds the lowest of the following three
conditions: 1) 1.5 times the voltage on the SS pin, 2) 1.5
times the voltage on the I
LIM
pin or 3) 1.5V. When a
current limit condition is sensed, all four external FETs are
immediately shut off. These devices are turned back on
only after C
T
reaches the same state (either charging or
OPERATIOU
discharging) as when the current limit condition oc-
curred. For instance, if C
T
is charging when current limit
occurs, the outputs are forced off for the remainder of this
charging time, the entire C
T
discharge time, and are only
re-enabled when C
T
reaches its valley voltage and begins
charging again. An analogous sequence of events occurs
if current limit is tripped while C
T
is being discharged.
The full-bridge current can be soft-started (gradually
increased) by placing a capacitor from the SS pin to
ground. A 1.5
μ
A current is sourced from the chip and will
charge the capacitor. This limits the inrush current at start-
up and allows the current delivered to the TEC to be linearly
increased from zero.
The LTC1923 features a dedicated pin, I
LIM
, to adjust
current limit. If the voltage placed on I
LIM
is greater than
1V, the default current limit, I
LIMIT
, is:
I
LIMIT
= 150mV/R
S
where R
S
= the current sense resistor.
Utilizing the I
LIM
pin allows the current limit threshold to
be easily set and adjusted (the current limit threshold can
also be adjusted by changing R
S
). More importantly, it
facilitates independent setting of the heating and cooling
current limits with the addition of one transistor. Figure 4
shows how to implement this using three resistors and an
external NMOS, M1. In many applications, a higher cool-
ing capability is desired. When TEC
+
is greater than
TEC
–
, the H/C output is in a low state signifying that the
system is being cooled (this is typical for most lasers).
–
+
A = 10
R
2R
1V
NDRVB
CURRENT SENSE
AMPLIFIER
PULSE-BY-PULSE
CURRENT LIMIT
TEC
–
CS
+
CS
–
NDRVA
TEC
+
NDRVB
OSCILLATOR
PEAK/VALLEY
NDRVA
I
TEC
I
LIM
SS
1.5
μ
A
INPUT SELECT
LEB
S
1923 F03
SHUT
OUTPUTS
OFF
R
Q
–
–
+
Figure 3. Current Sense Circuitry
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC1923EGN | High Efficiency Thermoelectric Cooler Controller |
| LTC1923EUH | High Efficiency Thermoelectric Cooler Controller |
| LTC1929IG | Isolated Flyback Switching Regulator with 9V Output |
| LTC1929C | Isolated Flyback Switching Regulator with 9V Output |
| LTC1929CG | Isolated Flyback Switching Regulator with 9V Output |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1923EGN | 功能描述:IC CONTROLLER TEC HI EFF 28SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:手持/移動設(shè)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(yīng)商設(shè)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 |
| LTC1923EGN#PBF | 功能描述:IC CONTROLLER TEC HI EFF 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:手持/移動設(shè)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(yīng)商設(shè)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 |
| LTC1923EGN#TR | 功能描述:IC CONTROLLER TEC HI EFF 28SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:手持/移動設(shè)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(yīng)商設(shè)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 |
| LTC1923EGN#TRPBF | 功能描述:IC CONTROLLER TEC HI EFF 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:手持/移動設(shè)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(yīng)商設(shè)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 |
| LTC1923EGNPBF | 制造商:Linear Technology 功能描述:Thermoelectric Cooler Controller SSOP28 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。