MIC2358YLQ
IEEE 802.3af Octal Power Sourcing
Equipment Controller
General Description
The MIC2358YLQYLQ octal network power controller is
designed for use in IEEE 802.3af-compliant power-
sourcing equipment (PSE). The device provides
standardized powered devices (PD) detection,
classification, current-limit, and monitoring of both DC
and AC maintain power signatures.
The MIC2358YLQYLQ can operate autonomously or be
controlled by software through a SMBus-compatible
interface. Its five address inputs support 32 unique
MIC2358YLQ addresses allowing control and monitoring
up to 256 powered Ethernet ports (32 MIC2358YLQ
devices) by an external management application.
For each port, the MIC2358YLQ uses external N-
Channel power FETs and current sense resistors to
deliver and monitor power. State machines have been
incorporated into this device for complete configuration,
fault reporting, and status on a per-port basis, including
port voltage and current.
The MIC2358YLQ also implements Micrel’s shared
power management and port prioritization which offers
more flexible allocation of available power among the
ports.
Throughout this document the term 802.3af is
synonymous for IEEE Std 802.3-2005.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
•
Fully compliant with the IEEE 802.3af Power-over-
Ethernet standard
•
Controls eight independent 48V-powered Ethernet
ports
•
Powered port attributes:
– Up to 15.4W delivered per port
– Input over-voltage protection (OVP)
– Powered Device detection and classification
– Active current limit
– Powered Device AC and DC disconnect
supported
•
Operates autonomously or by SMBus control
•
5-bit programmable digital addressing allows control
of up to 256 Ethernet powered ports
•
Hardware fault interrupt output
•
Available in a Pb-free 64-pin LQFP package
Applications
•
IEEE 802.3af Compliant Enterprise Switches/Hubs
•
IEEE 802.3af Compliant Endpoint and Midspan
Power Sources
•
PSE Power Injectors
•
IP Phone Systems
•
DTE Power Distribution
_________________________________________________________________________________________________________
Ordering Information
Part Number
MIC2358YLQYLQ
Temperature Range
0 °C to +70 °C
Pb-Free Package
64-Pin LQFP
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
July 2010
M9999-070810
Micrel, Inc.
MIC2358YLQ
Functional Block Diagram – Global Level
Revision History
Rev.
1.0
1.1
Date
12/08/09
05/03/10
Reason
Initial Created
Autonomous enable is low true max current (5V) is 40mA
July 2010
2
M9999-070810
Micrel, Inc.
MIC2358YLQ
Pin Configuration
ACSENSE
ACDRIVE
SDAOUT
/SMBINT
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
P1OUTPOS
P1OUTNEG
P1GATE
P1SENSE
P2OUTPOS
P2OUTNEG
P2GATE
P2SENSE
P3OUTPOS
P3OUTNEG
P3GATE
P3SENSE
P4OUTPOS
P4OUTNEG
P4GATE
P4SENSE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
P8OUTPOS
P8OUTNEG
P8GATE
P8SENSE
P7OUTPOS
P7OUTNEG
P7GATE
P7SENSE
P6OUTPOS
P6OUTNEG
P6GATE
P6SENSE
P5OUTPOS
P5OUTNEG
P5GATE
P5SENSE
ENABLE
SPMBUS
ICO
64-Pin LQFP (V)
July 2010
3
ASPMREF
DRTN
DCMPS
ACMPS
DRTN
RDET
ARTN
ARTN
NC
ALTB
5VS
NC
48VS
/RESET
ADDR1
ADDR2
ADDR3
ADDR4
ADDR5
SDAIN
DRTN
DRTN
SCL
/CS
NC
M9999-070810
Micrel, Inc.
MIC2358YLQ
Pin Description
Pin Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Pin Name
P1OUTPOS
P1OUTNEG
P1GATE
P1SENSE
P2OUTPOS
P2OUTNEG
P2GATE
P2SENSE
P3OUTPOS
P3OUTNEG
P3GATE
P3SENSE
P4OUTPOS
P4OUTNEG
P4GATE
P4SENSE
NC
ENABLE_L
Pin Function
Port 1 Positive 48V Terminal Input.
Port 1 Negative 48V Terminal Input.
Port 1 Gate Drive Output: Connect this pin to the gate terminal of Port 1’s external power
FET.
Port 1 Sense Input: Connect this pin the source terminal of Port 1’s external power FET.
Port 2 Positive 48V Terminal Input.
Port 2 Negative 48V Terminal Input.
Port 2 Gate Drive Output: Connect this pin to the gate terminal of Port 2’s external power
FET.
Port 2 Sense Input: Connect this pin the source terminal of Port 2’s external power FET.
Port 3 Positive 48V Terminal Input.
Port 3 Negative 48V Terminal Input.
Port 3 Gate Drive Output: Connect this pin to the gate terminal of Port 3’s external power
FET.
Port 3 Sense Input: Connect this pin the source terminal of Port 3’s external power FET.
Port 4 Positive 48V Terminal Input.
Port 4 Negative 48V Terminal Input.
Port 4 Gate Drive Output: Connect this pin to the gate terminal of Port 4’s external power
FET.
Port 4 Sense Input: Connect this pin the source terminal of Port 4’s external power FET.
No connection.
Autonomous mode select pin Input. When high, all ports are disabled on power up and can
only be enabled via SMBus interaction. When low, all ports are enabled on power up and
device operation will proceed without SMBus interaction necessary. Internally pulled up to
+5V by a 50kΩ resistor.
Autonomous mode select pin Input. When high all ports will be configured for Alt B operation,
when low all ports will be configured for Alt A operation. Internally pulled up to +5V by a 50kΩ
resistor.
Autonomous mode select pin Input. When high, ports will not have power removed if its
current exceeds the class-dependent overload current, i.e. overload current will be equal to
Class 0 Level. Internally pulled up to +5V by a 50kΩ resistor.
Autonomous mode select pin Input. When high, AC Maintain Power Signature feature is
enabled. Internally pulled up to +5V by a 50kΩ resistor.
Autonomous mode select pin Input. When high, DC Maintain Power Signature feature is
enabled. Internally pulled up to +5V by a 50kΩ resistor.
+5V Supply Voltage: Applying a +5V supply relative to 48VRTN powers the MIC2358YLQ’s
internal digital circuits, state machines, and port control circuits.
No connection.
Digital Ground Return.
48V Power Supply Input: In a negative common application, applying a conditioned +48V
supply (+44V
≤
48VS
≤
+60V) provides the supply voltage to power the MIC2358YLQ and all
eight ports. In a positive common application, apply system COM to this pin.
Digital Ground Return.
Analog Ground Return.
Analog Ground Return.
19
ALTB
20
ICO
21
22
23
24
25
26
ACMPS
DCMPS
5VS
NC
DRTN
48VS
27
28
29
DRTN
ARTN
ARTN
July 2010
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M9999-070810
Micrel, Inc.
Pin Number
30
31
Pin Name
SPMREF
SPMBUS
Pin Function
MIC2358YLQ
Shared Power Management Reference Resistor. Connect an external 250kΩ, 1% resistor
from this pin-to-ARTN.
Shared Power Management Buss. A resistor connected from this pin to ARTN sets the total
power allocated to all ports in use. For all eight ports, the total maximum allocated power is
123.2W (15.4W x 8 ports). The transfer characteristic for this pin is 2.5V/R
SPMREF
per Watt.
Thus, the resistor value is determined by R
SPMREF
/P
TOTAL.
PD Signature Detection Resistor. Connect a 1kΩ 1% resistor from this pin to ARTN.
Port 5 Sense Input: Connect this pin the source terminal of Port 5’s external power FET.
Port 5 Gate Drive Output: Connect this pin to the gate terminal of Port 5’s external power
FET.
Port 5 Negative 48V Terminal Input.
Port 5 Positive 48V Terminal Input.
Port 6 Sense Input: Connect this pin the source terminal of Port 6’s external power FET.
Port 6 Gate Drive Output: Connect this pin to the gate terminal of Port 6’s external power
FET.
Port 6 Negative 48V Terminal Input.
Port 6 Positive 48V Terminal Input.
Port 7 Sense Input: Connect this pin the source terminal of Port 7’s external power FET.
Port 7 Gate Drive Output: Connect this pin to the gate terminal of Port 7’s external power
FET.
Port 7 Negative 48V Terminal Input.
Port 7 Positive 48V Terminal Input.
Port 8 Sense Input: Connect this pin the source terminal of Port 8’s external power FET.
Port 8 Gate Drive Output: Connect this pin to the gate terminal of Port 8’s external power
FET.
Port 8 Negative 48V Terminal Input.
Port 8 Positive 48V Terminal Input.
Reset Input: This active LOW asserted digital input is used to reset the MIC2358YLQ to
default settings. There is an internal 50kΩ resistor connected from this pin to 5VS.
Do not connect.
Digital Ground. Connect this pin to all other MIC2358YLQ DRTN pins at one point.
Internal AC Oscillator output. Accessible from this pin is the MIC2358YLQ’s internal oscillation
specifically required to support AC Disconnect. An 83Hz square wave with 50% is available.
Senses the AC Drive forced on positive port terminals. Connect to V48 through 800Ω and
diode even if AC disconnect is not used. Please see reference schematic.
SMBus Serial Clock Input. External pull up resistor required.
SMBus Serial Data Output.
SMBus Serial Data Input. External pull up resistor required.
Digital Ground. Connect this pin to all other MIC2358YLQ DRTN pins at one point.
SMBus Interrupt open-drain output. External pull up resistor required.
Address Chip Select Input. This bit is internally pulled up to +5V by a 50kΩ resistor.
SMBus Address Bit 5 (MSB): This address bit is the most significant bit of the MIC2358YLQ’s
5-bit address bank. This bit is internally pulled up to +5V by a 50kΩ resistor.
SMBus Address Bit 4: This bit is internally pulled up to +5V by a 50kΩ resistor.
SMBus Address Bit 3: This bit is internally pulled up to +5V by a 50kΩ resistor.
SMBus Address Bit 2: This bit is internally pulled up to +5V by a 50kΩ resistor.
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
RDET
P5SENSE
P5GATE
P5OUTNEG
P5OUTPOS
P6SENSE
P6GATE
P6OUTNEG
P6OUTPOS
P7SENSE
P7GATE
P7OUTNEG
P7OUTPOS
P8SENSE
P8GATE
P8OUTNEG
P8OUTPOS
/RESET
NC
DRTN
ACDRIVE
ACSENSE
SCL
SDAOUT
SDAIN
DRTN
/SMBINT
/CS
ADDR5
ADDR4
ADDR3
ADDR2
July 2010
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M9999-070810