參數(shù)資料
型號(hào): MAX3280
廠商: Maxim Integrated Products, Inc.
元件分類: RS-485
英文描述: 【15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23 RS-485/RS-422 True Fail-Safe Receivers
中文描述: 【15kV ESD保護(hù)52Mbps的,3V至5.5V,SOT23封裝的RS-485/RS-422真正的失效保護(hù)接收器
文件頁(yè)數(shù): 6/11頁(yè)
文件大?。?/td> 218K
代理商: MAX3280
M
users design equipment that meets Level 3 of IEC 1000-
4-2, without additional ESD-protection components.
The main difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2. Because series resistance is
lower in the IEC 1000-4-2 ESD test model (Figure 4a),
the ESD-withstand voltage measured to this standard is
generally lower than that measured using the Human
Body Model. Figure 4b shows the current waveform for
the ±8kV IEC 1000-4-2 Level 4 ESD Contact Discharge
test. The Air-Gap test involves approaching the device
with a charger probe. The Contact Discharge method
connects the probe to the device before the probe is
energized.
Machine Model
The Machine Model for ESD testing uses a 200pF stor-
age capacitor and zero-discharge resistance. It mimics
the stress caused by handling during manufacturing
and assembly. All pins (not just the RS-485 inputs)
require this protection during manufacturing. Therefore,
the Machine Model is less relevant to the I/O ports than
are the Human Body Model and IEC 1000-4-2.
True Fail-Safe
The MAX3280E/MAX3281E/MAX3283E/MAX3284E
guarantee a logic-high receiver output when the receiv-
er inputs are shorted or open, or when they are connect-
ed to a terminated transmission line with all drivers
disabled. This guaranteed logic high is achieved by set-
ting the receiver threshold between -50mV and -200mV.
If the differential receiver input voltage (A-B) is greater
than or equal to -50mV, RO is logic high. If (A-B) is less
than or equal to -200mV, RO is logic low.
In the case of a terminated bus with all transmitters dis-
abled, the receiver
s differential input voltage is pulled
to ground by the termination. This results in a logic high
with a 50mV minimum noise margin. Unlike previous
fail-safe devices, the -50mV to -200mV threshold com-
plies with the ±200mV EIA/TIA-485 standard.
Receiver Enable
(MAX3281E and MAX3283E only)
The MAX3281E and MAX3283E feature a receiver out-
put enable (EN, MAX3281E or
EN
, MAX3283E) input
that controls the receiver. The MAX3281E receiver
enable (EN) pin is active high, meaning the receiver
outputs are active when EN is high. The MAX3283E
receiver enable (
EN
) pin is active low. Receiver outputs
are high impedance when the MAX3281E
s EN pin is
low and when the MAX3283E
s
EN
pin is high.
Low-Voltage Logic Levels
(MAX3284E only)
An increasing number of applications now operate at
low-voltage logic levels. To enable compatibility with
these low-voltage logic level applications, such as digi-
tal FPGAs, the MAX3284E V
L
pin is a user-defined sup-
ply voltage that designates the voltage threshold for a
logic high.
At lower V
L
voltages, the data rate will also be lower. A
logic-high level of 1.65V will receive data at 20Mbps.
Table 2 gives data rates at various voltages at V
L
.
Applications Information
Propagation Delay Matching
The MAX3280E/MAX3281E/MAX3283E/MAX3284E
(V
CC
= V
L
) exhibit propagation delays that are closely
matched from one device to another, even between
devices from different production lots. This feature
allows multiple data lines to receive data and clock sig-
nals with minimal skew with respect to each other.
Figure 5 shows the typical propagation delays. Small
receiver skew times, the difference between the low-to-
high and high-to-low propagation delay, help maintain a
symmetrical ratio (50% duty cycle). The receiver skew
time | t
PLH
- t
PHL
| is under 2ns for either a 3.3V supply
or a 5V supply.
Multidrop Clock Distribution
Low package-to-package skew (8ns max) makes the
MAX3280E/MAX3281E/MAX3283E/MAX3284E
(V
CC
= V
L
) ideal for multidrop clock distribution. When
distributing a clock signal to multiple circuits over long
transmission lines, receivers in separate locations, and
possibly at two different temperatures, would ideally
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
6
_______________________________________________________________________________________
PART
ENABLE = HIGH
Active
High Z
ENABLE = LOW
High Z
Active
MAX3281E
MAX3283E
Table 1. MAX3281E/MAX3283E Enable
Table
V
CC
= 3V TO 5.5V
V
L
MAXIMUM DATA RATE
20Mbps
33Mbps
52Mbps
1.65V
2.2V
3.3V
Table 2. MAX3284E Data Rate Table
相關(guān)PDF資料
PDF描述
MAX3281EAUT-T 【15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23 RS-485/RS-422 True Fail-Safe Receivers
MAX3284EAUT-T 【15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23 RS-485/RS-422 True Fail-Safe Receivers
MAX3280EAUK 【15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23 RS-485/RS-422 True Fail-Safe Receivers
MAX3280E 32-Bit Digital Signal Controller with Flash 100-BGA MICROSTAR -40 to 85
MAX3291 32-Bit Digital Signal Controller with Flash 128-LQFP -40 to 85
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX3280EAUK 制造商:Maxim Integrated Products 功能描述:+/-15KV ESD-PROTECTED 52MBPS 3V TO - Rail/Tube 制造商:Rochester Electronics LLC 功能描述:
MAX3280EAUK/V+ 制造商:Maxim Integrated Products 功能描述:- Rail/Tube
MAX3280EAUK/V+T 功能描述:RS-422/RS-485 接口 IC RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)速率:1136 Kbps 工作電源電壓:3 V to 5.5 V 電源電流:5.9 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-28 封裝:Tube
MAX3280EAUK+ 制造商:Maxim Integrated Products 功能描述:LINE RCVR 1RX 5PIN SOT-23 - Rail/Tube
MAX3280EAUK+T 功能描述:RS-422/RS-485 接口 IC 52Mbps 3-5.5V RS-485 422 Fail Safe Rcvr RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)速率:1136 Kbps 工作電源電壓:3 V to 5.5 V 電源電流:5.9 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-28 封裝:Tube