PBL 386 30/2
may be applied to the SLIC.
transients and therefore will not protect the
SLIC.
crowbar into a low voltage on-state condi-
tion, by firing an internal thyristor.
A gate decoupling capacitor, C GG, is
needed to carry enough charge to supply a
high enough current to quickly turn on the
Secondary Protection
Power-up Sequence
No special power-up sequence is neces-
sary except that ground has to be present
before all other power supply voltages.
Thecircuitshowninfigure11utilizesseries
resistors together with a programmable
overvoltage protector
(e.g. Power Innovations TISPPBL2), serv-
ing as a secondary protection.
The TISPPBL2 is a dual forward-con-
ducting buffered p-gate overvoltage pro-
tector. The protector gate references the
protection (clamping) voltage to negative
supply voltage (i e the battery voltage, VB).
As the protection voltage will track the
negative supply voltage the overvoltage
stress on the SLIC is minimized.
Positive overvoltages are clamped to
ground by a diode. Negative overvoltages
areinitiallyclampedclosetotheSLICnega-
tivesupplyrailvoltageandtheprotectorwill
thyristor in the protector. C
shall be
GG
placed close to the overvoltage protection
device. Without the capacitor even the low
inductanceinthetracktotheVBatsupplywill
limit the current and delay the activation of
the thyristor clamp.
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 ex-
posed to a power cross.
Printed Circuit Board Layout
CareinPCBlayoutisessentialforproper
function. The components connecting to
the RSN input should be placed in close
proximitytothatpin, sothatnointerference
is injected into the RSN pin. Ground plane
surrounding the RSN pin is advisable.
Analog ground (AGND) should be con-
nected to battery ground (BGND) on the
PCB in one point.
If a PTC is chosen for RF, note that it is
important to always use PTC´s in series
with resistors not sensitive to temperature,
asthePTCwillactasacapacitanceforfast
The capacitors for the battery should be
connected with short wide leads of the
same length.
Ordering Information
Package
Temp. Range
Part No.
PBL 386 30/2SHT
PBL 386 30/2SOS
PBL 386 30/2SOT
24 pin SSOP Tape & Reel -40° - +85° C
24 pin SOIC Tube -40° - +85° C
24 pin SOIC Tape & Reel -40° - +85° C
28 pin PLCC Tube
-40° - +85° C PBL 386 30/2QNS
28 pin PLCC Tape & Reel -40° - +85° C
PBL 386 30/2QNT
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. 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 386 30/2 Uen Rev. B
© Ericsson Microelectronics AB 2000
This product is an original Ericsson
product protected by US, European and
other patents.
Ericsson Microelectronics AB
SE-164 81 Kista-Stockholm, Sweden
Telephone: +46 8 757 50 00
16
ERICSSON [ ERICSSON ]
