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参数资料
| 型号： | A8291SETTR-T |
| 厂商： | Allegro Microsystems Inc |
| 文件页数： | 8/19页 |
| 文件大小： | 0K |
| 描述： | IC VOLTAGE REG SGL LNB 28-QFN |
| 标准包装： | 9,000 |
| 应用： | 转换器，模拟和数字式卫星信号接收器 |
| 输入电压： | 8 V ~ 16 V |
| 输出数： | 1 |
| 输出电压： | 12.7 V ~ 20.4 V |
| 工作温度： | -20°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-VFQFN 裸露焊盘 |
| 供应商设备封装： | 28-QFN/MLP 裸露焊盘（5x5） |
| 包装： | 带卷 (TR) |
A8291
Single LNB Supply and Control Voltage Regulator
been removed. Consecutive startup attempts should allow at least
2 s of delay between restarts.
In-Rush Current
At start-up or during an LNB reconfiguration event, a tran-
sient surge current above the normal DC operating level can be
provided by the A8291. This current increase can be as high as
600 mA, typical, for as long as required, up to a maximum of
48 ms.
Tone Detection
A 22 kHz tone detector is provided in the A8291 solution. The
detector extracts the tone signal and provides it as an open-drain
signal on the TDO pin. The maximum tone out error is ±1 tone
cycle, and the maximum tone out delay with respect to the input
is 1 tone cycle. Detection thresholds are given in table 1.
Tone Generation
The A8291 solution offers four options for tone generation,
(options 1 or 2), the minimum tone detect amplitude is 400 mV,
and when an external tone is used (options 3 or 4), the minimum
tone detection amplitude is 300 mV.
DiSEqC? Bypass MOSFET
A pair of N-channel MOSFETs are connected in parallel (source
to drain and drain to source) to provide a low source output
impedance during tone transmission.
The MOSFETs are enabled either via the BFC input pin (ac-
tive low) or by setting the BFC2 bit to 1 in the Control register.
When the BFC pin is used instead of I 2 C? control, it is not
latched; a logic high or low turns the FET off or on. When the
EXTM
TMODE
TGATE
Tone
providing maximum flexibility to cover every application. The
(LNB Ref)
LNB (V)
(LNB Ref)
EXTM pin (external modulation), in conjunction with the I 2 C?
control bits: TMODE (tone modulation) and TGATE (tone gate),
provide the necessary control. The TMODE bit controls whether
the tone source is either internal or external (via the EXTM pin).
Both the EXTM pin and TGATE bit determine the 22 kHz con-
trol, whether gated or clocked.
Four options for tone generation are shown in figure 1. Note
that when using option 4, when EXTM stops clocking, the LNB
volts park at the LNB voltage, either plus or minus half the tone
signal amplitude, depending on the state of EXTM. For example,
if the EXTM is held low, the LNB dc voltage is the LNB pro-
grammed voltage minus 325 mV (typical).
With any of the four options, when a tone signal is generated,
TDET is set in the status register. When the internal tone is used
Table 1. Detection Thresholds for Tone Generation Options
Transmit Receive
Option 1 – Use internal tone, gated by the TGATE bit.
EXTM
TMODE
TGATE
Tone
LNB (V)
Option 2 – Use internal tone, gated by the EXTM pin.
EXTM
TMODE
TGATE
Option
(Fig. 1)
TMODE
1
1
2
1
3
0
4
0
n.a.
0
n.a.
1
Tone
(LNB Ref)
LNB (V)
1
TGATE
EXTM
Control
0/1
1
1
Control
0/1
Control
0/1
Control
22 kHz gated
logic signal, 22 kHz
continuous logic
signal
At least one must
be 0 to prevent
tone transmission
Option 3 – Use external tone, gated by the TGATE bit.
EXTM
TMODE
Guaranteed
Detection
Threshold
(mV PP )
Rejection
Threshold
(mV PP )
400
100
400
100
300
100
300
100
300
100
400
100
TGATE
Tone
(LNB Ref)
Option 4 – Use external tone.
Figure 1. Options for tone generation
LNB (V)
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
8
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相关代理商/技术参数 |
参数描述 |
|---|---|
| A8291SETTR-TB | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:Single LNB Supply and Control Voltage Regulator |
| A8292 | 制造商:AMPEX 功能描述: |
| A8292SETTR-T | 功能描述:IC REG LNB SUPPLY/CONTROL 28-MLP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器，DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP（0.173"，4.40mm 宽） 供应商设备封装:30-TSSOP 包装:带卷 (TR) |
| A8293 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:Single LNB Supply and Control Voltage Regulator |
| A8293SESTR-T | 功能描述:IC REG LNB BOOST/LINEAR 20-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
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