HV110
(cont.) (at 0°C < T < +75°C, unless otherwise specified)
Electrical Characteristics
A
Sym
Parameter
Min
Typ Max Units Conditions
VOLPWRGD PWRGD output low voltage
-
-
-
-
-
-
-
-
-
-
-
0.4
V
I = 3.0mA; Referenced to VNN
V = 5.0V; Referenced to VNN
Measured at TA = 25°C
Measured at TA = 25°C
Measured at TA = 25°C
Measured at TA = 25°C
Measured at TA = 25°C
IOHPWRGD PWRGD output leakage current
-
10
-
µA
ms
ms
ms
µs
tSC
tUC
Shorted-circuit timer3
Under-current timer4
Over-current timer5
Current limit delay time6
POR timer
60
350
60
10
3.5
9.0
140
20
-
tOC
-
tLIMIT
tPOR
tRESTART
TOT
-
-
ms
Restart timer
-
sec Measured at TA = 25°C
Over temperature trip limit
Temperature hysteresis
-
OC
OC
---
---
THYS
-
Notes:
1. The HV110 will work in both positive and negative voltage applications, the maximum differential voltage between the VPP and VNN pins must not be exceeded.
2. UVLO Threshold to be modified using external resistors, when a Zener diode is connected to VPP pin. (See Signature Detection)
3. Shorted-circuit timer starts after POR timer. If VOUT does not charge at least 90% VIN before tSC then a shorted-circuit condition exists.
4. Under-current timer starts when IOUT goes below IMIN. If IOUT stays below IMIN longer than tUC then MOSFET is turned off due to under current condition.
5. If the output current is in an overload or shorted load condition then the output immediately goes to current limit and starts the over-current timer. If IOUT does not drop
back below ILIMIT before the timer expires then an over current condition exists. The timer is immediately reset when a fault is cleared.
6. Time for fast return to limit circuit to react.
Functional Block Diagram
VPP
HV110
Temperature
Sensor
Regulator
UVLO
24MΩ
PWRGD
UVLO
Control
Logic
POR
Timer
116kΩ
Restart
Timer
VNN
DRAIN
Powered Ethernet Requirements
Power-over-LAN (sometimes called Powered Ethernet or The IEEE802.3af standard specifies the requirements, fea-
Powered VoIP) is the general concept of providing high volt- tures and characteristics of the PSE and PD devices for use
age (48VDC) power over existing networking cables, such in PoE applications. The HV110 is a PD controller IC, ca-
as Ethernet cables. This is accomplished either by using pable of handling all the current and timing requirements of
the CAT5 Ethernet Cable’s unused spare pairs or the signal the IEEE802.3af standard.
pairs (ENV B vs. ENV A).
A PD designed to this standard and within its range of avail-
In Power-over-LAN applications there are two main types of able power, can obtain both power and data for operation via
equipment: the Power Sourcing Equipment (PSE) and the the standard LAN cables and therefore will not require any
Powered Device (PD). There is a third type called Mid-Span additional power sources or connections.
equipment that plugs in line and converts a conventional
router into a PSE.
3
SUPERTEX [ Supertex, Inc ]
