
Ericsson Internal
Prepared (also subject responsible if other)
EMQTUWX 3/1301-BMR 629 8210 Uen
Approved Checked Date Rev Reference
EMAOLII 2012-09-26 D
Inhibit Control
The products are fitted with
a remote contr ol function
by us ing the Inhibit/UVLO
pin. The I nhi bit control
function allows the product
to be turned on/off by an
external device like a
semiconductor or
mechanical switch.
pin has an internal pull up.
An external pu ll-up resist or
should never be used with
the inhibit pin.
When the Inhibit pin is left op en, the regulator will turn o n
when the input v ol tage is applied. Turn off i s achieved by
connecting the Inhibit pin to the GND.
The reference figure above shows the typical application of
the inhibit func tion. The i nput is not compat ible with TTL logic
device. An ope n-collector (or open-drain) discrete transistor is
recommended for control. Turning the discr ete transistor on
applies a low voltage to the I nhi bit control pi n and disables the
output of the module. If this device is then turned off, the
module executes a soft-start power-up sequence. A reg ul ated
output voltage is produced within 20 ms.
External Decoupling Capacitors
The PMR 8210 requires a minim um i nput capacitance of e
1000 µF. The ripple current rating of the input capacitor must
be at least 750 mA rms. An optional 22 µF X5R/X7R ceramic
capacitor is r ecommended to reduce RMS ripple current.
The size and value of the input capac itor is determined by the
converter’s transient performance capability. This minimum
value assumes that the converter is supplied with a
responsive, low inductance input source. This source s hould
have ample capacitive decoupling, an d be distributed to the
converter vi a P C B power and ground planes.
Ceramic capacitors should be located as close as possible to
the module's input pins, withi n 0.5 inch (1,3 cm). Adding
ceramic capacitance is necessary to reduce the high-
frequency ripp le voltage at t he module's input. This reduces
the magnitud e of the ripple current through t he electrolytic
capacitor, as well as the amount of ripple curr ent reflected
back to the input source. Add itional ceram ic capacitor s can be
added to further reduce the RMS ripple current requirement
for the electrolytic capacitor .
The main considerations when selecting input capacitors are
the RMS ripple current rating, temperatur e stability, and less
than 100 mΩ of equivalent series resistance (ESR).
Regular tant al um capacitors are not recommended for the
input bus. These capacitors require a recommended
minimum voltage rating of 2× (maximum dc voltage + ac
ripple). This is standard practice to ensure reliability. No
tantalum capacitors were found with a sufficient voltage rating
to meet this requirement.
Output capac itors:
The PMR 8210 module requir es a minimum output
capacitanc e of 1000µF of polym er-aluminum, tantulum, or
polymer-tant alum type.
The required c apacitance abo ve the minimum is determine d
by actual transient deviat i on requirements. See
“TurboTrans Technology” information below.
For both input and output capacitors, when the operating
temperature is below 0°C, the ESR of aluminium electrolytic
capacitors inc reases. For these applications, OS -CON, poly-
aluminium, and polymer-ta ntalum types should be considered.
If the TurboTrans feature is not used, minimum ESR and
maximum capacitor limits must be followed. System stability
may be effected and increased output capacitance may be
required without TurboTrans.
When using th e PMR 8210, obser ve the minimum ESR of the
entire output capacitor bank. The minimum ESR limit of the
output capacitor bank is 7mΩ.
When using PMR 8210 without the TurboTrans feature, the
maximum amount of capacitanc e i s 1000 µF of cer amic type.
Large amounts of capacita nc e may reduce system stability.
Utilizing the TurboTrans feature improves system stabili ty,
improves tra ns ient response, and reduces the amount of
output capacit ance required to meet system transient design
requirements. For detaile information, see “TurboTrans
Technology” information below.
Output Voltage Adjust (Vadj)
The product has an Output Vo l tage Adjust function. The
function can be used to adjust t he output voltage in the range
from 3.0V to 5.25V.
The Vo Adjust control sets the output voltage of the PMR
8210. The adjustment method requires the addition of a single
external resis tor, RSET , that must be connected directl y
between pins Vo Adjust (pin 18) and AGND (pin 4) . The value
of the required resistor can b e calculated using the following
formula.
(Ω−
−
=k25.8
0.7
-
7.0
O
V
7.0
SET
R
Note:
(1) SET
R: Use a 0.05 W resistor with a tolerance of 1% and
temperature s tability of 100 ppm/°C (or better). Connect the
E
PMR 8000 series PoL Regulator
Input 8 - 14 V, Output up to 40 A / 210 W
EN/LZT 146 411 R1C March 2013
© Ericsson AB
Technical Specification