参数资料
| 型号： | MIC2555-1BML TR |
| 厂商： | Micrel Inc |
| 文件页数： | 5/29页 |
| 文件大小： | 0K |
| 描述： | IC TXRX UTG USB BUS UNIV 24MLF |
| 标准包装： | 1,000 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 1/0 |
| 规程： | USB 2.0 |
| 电源电压： | 3 V ~ 4.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-VFQFN 裸露焊盘，24-MLF? |
| 供应商设备封装： | 24-MLF?（4x4） |
| 包装： | 带卷 (TR) |
| 其它名称： | MIC2555-1BMLTR |
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Micrel, Inc.
MIC2555
December 2006
13
M9999-121406
VBUS Comparators
VBUS Comparators monitor the voltage level of VBUS.
As described in the USB On-The-Go Supplement, VBUS
not only supplies power but also is used to signal various
operational conditions as part of the SRP protocol.
Depending upon the voltage on VBUS, three states of
operation can be defined:
VBUS Valid
Session Valid
Session End.
VBUS Valid Comparator
This comparator is used by an A-device to determine
whether the voltage on VBUS is at a valid level for
operation. The minimum threshold for the VBUS valid
comparator is 4.4V. Any voltage on VBUS below the
threshold of the VBUS valid comparator is considered a
fault. During power up, it is expected that this
comparator’s output will be ignored.
Session Valid Comparator
The session valid comparator determines when VBUS is
high enough for a session to start. Both the A-device and
B-device use this comparator to detect when a session
is being started. The A-device also uses this comparator
to indicate when a session is over.
The session valid window for an A-device is 0.8 – 2.0V
while the session valid window for a B-device is 0.8 –
4.0V. Because these ranges overlap the A-device
window is typically chosen to service both requirements
and a single comparator can be used. This is the case
with MIC2555.
Session End Comparator
The USB OTG Supplement specifies that a B-device
cannot initiate SRP unless VBUS is below the B-device
Session End threshold of 0.8V. Monitoring VBUS with a
comparator will give an exact and positive determination
of when VBUS has dropped below 0.8V, but the USB
OTG supplement allows that the 0.8V limit can also be
inferred, by discharging VBUS through a low value
resistor for a predetermined period. The MIC2555
provides both a session-end comparator and a
discharging resistor. To accommodate either technique,
the designer can use them individually or, in concert as
he so chooses.
Pull-up/down Resistors on D+, D-
MIC2555 supplies the pull-up and pull-down resistors for
termination
and
signaling
required
by
USB
specifications. These resistors are integrated within the
chip and switched into the circuit, as needed, via
individual control bits in the control registers.
Single
Ended
Decoder
DAT_VP
SE0_VM
OE_INT/
RCV
Controlled by
Register Bits
1.5k
VTRM
Controlled by
Register Bits
1.5k
Resistors and Circuitry associated with D+, D– Pins
ID Detector
The ID function, defined within the USB On-The-Go
supplement, represents a new addition to the USB
standard. It is used to detect the presence or removal of
a peripheral device as well as to differentiate between
USB and non-USB peripherals. ID is unique to the mini-
USB connectors and receptacles.
MIC2555’s ID Detector is operational in both the Active
and Suspended power modes, and differentiates
between three conditions:
ID Pin
Condition
Device Status
VID
Floating
No device
present
VID > 0.85VBAT
Grounded
USB device
present
VID < 0.15VBAT
Grounded
through a
Resistor
Non-USB
device present
0.15VBAT < VID >
0.85VBAT
Here, ‘Grounded through a Resistor’ means a resistor of
a
considerable
value,
typically
100k.
The
ID
comparators are set to ignore the modest resistances
contributed by the cables and connector contacts.
That a non-USB device is present (ID = resistive) is
inferred from the interrupt register by the indication of an
interrupt (ID has changed state) and that neither ID =
GND or ID = Float are true. Viewing the Interrupt source
register will give the real time status of the ID
comparator outputs. Viewing this register is necessary to
determine the true state of affairs as insertion of the USB
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| MIC2555-1YML | 制造商:Rochester Electronics LLC 功能描述: 制造商:RF Micro Devices Inc 功能描述: |
| MIC2555-1YML TR | 功能描述:USB 接口集成电路 USB Transceiver - Lead Free RoHS:否 制造商:Cypress Semiconductor 产品:USB 2.0 数据速率: 接口类型:SPI 工作电源电压:3.15 V to 3.45 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:WLCSP-20 |
| MIC2555-1YML-TR | 功能描述:1/1 Transceiver Half USB 2.0 24-MLF? (4x4) 制造商:microchip technology 系列:- 包装:剪切带（CT） 零件状态:有效 类型:收发器 协议:USB 2.0 驱动器/接收器数:1/1 双工:半 接收器滞后:200mV 数据速率:400kbps 电压 - 电源:3 V ~ 4.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:24-VFQFN 裸露焊盘，24-MLF? 供应商器件封装:24-MLF?（4x4） 标准包装:1 |
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