PBL 3764A/4, /6
track to the VBat supply will limit the
current and delay the activation of the
thyristor clamp.
Power-up Sequence
The voltage at pin VBAT sets the
Printed Circuit Board Layout
Care in PCB lay-out is essential for
substrate voltage, which must at all times proper PBL 3764A/4 function. The
be kept more negative than the voltage at components connecting to the RSN pin
any other pin to prevent possible latch-up. (16) should be in close proximity of that
The optimal power-up sequency is ground pin such that no interference is injected
and VBat, then other supplies and signal
leads.
The fuse resistors RF serve the dual
purposes of being non- destructive
energy dissipators, when transients are
clamped and of being fuses, when the
line is exposed to a power cross.
Ericsson Microelectronics AB offers a
series of thick film resistors networks (e g
PBR 51- series and PBR 53-series)
designed for this application.
Also devices with a built in resetable fuse
function is offered (e g PBR 52-series)
including positive temperature coefficient
(PTC) resistors, working as resetable
fuses, in series with thick film resistors.
Note that it is important to always use
PTC´s in series with resistors not
sensitive to temperature, as the PTC will
act as a capacitance for fast transients
and therefore the ability to protect the
SLIC will be reduced.
into the RSN terminal. Ground plane
surrounding the RSN pin is advisable.
The two ground pins AGND and BGND
However, VCC may be connected before
VBat and if the VBat supply voltage shuld be should be connected together on the
absent, a diode with a 2A current rating
connected with its cathode to VEE and
anode to VBAT ensures the presence of
the most-negative supply voltage at the
VBAT pin. The VBAT pin should not be
applied at a faster rate than corresponds
to the time constant formed by a 5.1Ω
resistor in series with the VBATpin and a
0.47 µF capacitor from the VBAT pin to
ground. This RC network may be shared
by several SLICs.
PCB at the device location.
If there is a risk for overvoltages on the
VBat terminal on the SLIC, then this
terminal should also be protected.
Ordering Information
Package
Temp. Range
Part No.
PDIP Tube
PLCC Tube
PLCC Tube
PLCC Tape & Reel
PLCC Tape & Reel
-40 to 85°C
-40 to 85°C
-40 to 85°C
-40 to 85°C
-40 to 85°C
PBL3764/4NS
PBL3764/4QNS
PBL3764/6QNS
PBL3764/4QNT
PBL3764/6QNT
Information given in this data sheet is believed to be
accurate and reliable. However no responsibility is
assumed for the consequences of its use nor for any
infringement of patents or other rights of third parties
which may result from its use. No license is granted
by implication or otherwise under any patent or
patent rights of Ericsson Microelectronics AB. These
products are sold only according to Ericsson
Microelectronics general conditions of sale, unless
otherwise confirmed in writing.
Specifications subject to change without
notice.
1522-PBL 3764+ Uen Rev. C
© Ericsson Microelectronics AB 1999
This product is an original Ericsson
product protected by US, European and
other patents.
Ericsson Microelectronics AB
S-164 81 Kista-Stockholm, Sweden
Telephone: +46(0)8 757 50 00
18
ERICSSON [ ERICSSON ]
