µTrenchMOS
Battery powered motor control
µTrenchMOS
Battery protection in Li-ion
powered applications
µTrenchMOS
MOSFET gate driver stage in DC/DC
converters using TSOP6
Description
In high-power DC/DC converters, synchronous rectification
is often used on the converter secondary side in order to
improve efficiency and minimise converter power loss.To
facilitate fast and efficient switching of the synchronous rec-
tifier MOSFETs, MOSFET gate driver stages are often used.
Each driver stage consists of one N-channel and one
P-channel MOSFET in a totem-pole configuration (Q3/Q4
for the upper power MOSFET Q1 and Q5/Q6 for the lower
power MOSFET Q2), the gate driver circuits are in turn
driven by a PWM controller situated on either the primary
or secondary side of the converter.
Benefits
• The V
GS
waveforms of the synchronous rectifier MOSFETs
show less ringing and under / overshoot
• Better V
GS
waveform stability compared with standard driv-
er stages (at low and high current demands)
• Synchronous rectifier I
G
waveforms are also more stable
with a MOSFET driver stage
• No effect on the behaviour of the power switching circuit
(compared with traditionally used driver components)
Suitable Products
• PMN34UN
• PMN34LN
• PMN27UN
• PMN28UN
<30 V MOSFETs
LFPAK for DC/DC converters
Description
Philips’ µTrenchMOS family in the very small TSOP6 can
be used to control small motors in range a of common
applications such as shavers and electric toothbrushes, as
well as a variety of industrial applications.The speed of
these small motors must remain constant whatever the
motor load, and hence the current through the MOSFET
varies during usage. R2 is used to sense the current
through the motor and MOSFET, and by monitoring the
voltage developed across R2 the controller is able to
maintain the motor at a constant speed, irrespective of
load. In the circuit below the MOSFET gate current can
be limited and any spikes generated by the motor are
suppressed.
Benefits
• Appropriate for driving motors in the 3-5 W power
range
• Low V
GS(th)
MOSFETs are capable of functioning at low
battery voltages (even single cell powering), and are in
extremely small packages
• No MOSFET snubber circuit required as the devices are
capable of handling high peak currents and voltages
• Efficient, very low R
DS(on)
specifications means no change
in motor speed due to voltage drops across the
MOSFET
Suitable Products
• PMN34UN
• PMN27UN
• PMN40LN
• PMN55LN
• PMN34LN
• PMN28UN
• PMN45EN
• PMN23UN
Description
The use of Li-ion batteries in modern hand-held
equipment is now very common, with applications
typically using between one and four cells depending on
individual power requirements. Protection of the cell(s) is
always necessary in order to prevent cell damage during
instances of over- or under-charging or short-circuit
conditions, and the protection scheme employed must be
able to isolate the battery from the rest of the circuit.
The circuit diagram below carries out the protection and
isolation function with the safety IC constantly
monitoring the (dis)charge current and the voltage across
the cell.When the cell is being (dis)charged correctly,
conduction will take place via both MOSFETs (turned
ON and with very low R
DS(on)
). When a fault condition
occurs, the MOSFET will be turned off disconnecting the
Li-ion cell from the rest of the circuit.
Benefits
• Very low on-state resistance, hence very low power loss
in the switches
• Good switching performance
• Very small PCB footprint and low package height
• Low threshold voltage enables MOSFET drive directly
from the battery voltage without the use charge pumps
Suitable Products
• PMWD26UN
• PMWD16UN
• PMWD15UN
Description
With the increasing importance of power density in
DC/DC converters, Philips’ solutions in LFPAK offer
greater power density than both SO8 and DPAK
products. Our devices offer leading performance in
applications such as Point of Load (POL) and VRMs,
whether in the low-side or high-side position, where
minimum switching losses are vital.
There is also a requirement for high component density,
thus a minimum number of small footprint MOSFETs
must be used. In higher current applications, an LFPAK
device can meet the thermal requirements that one SO8
cannot, and in these cases either two SO8 devices or a
DPAK would be needed.
Benefits
• Suitable for 5 V or 12 V gate drive
• Greater power density than SO8 or DPAK
• Same footprint area as SO8
Suitable Products
• PH3830L
• PH5330E
• PH7030L
• PH4530L
• PH3120L
• PMWD30UN
• PMWD19UN
• PMWD18UN
PMN40LN
PMN45EN
PMN55LN
PMN23UN
SiliconMAX and NQ series Power MOSFETs are suitable for use
in the Q1 and Q2 MOSFET positions.The PMN series are
suitable for use in Q3 and Q5 MOSFET positions
PMWD26UN
PMWD16UN
PMWD15UN
PMWD30UN
PMWD19UN
PMWD18UN
Typical R
DS(on)
mΩ
R @ 1.8 V Max
V
DS
(V) V
GS
=4.5 V V
GS
=2.5 V Typ (mΩ) V
GS
(V)
20
26.0
29.0
34
10
20
16.0
18.0
22
10
20
15.3
17.0
20
12
30
30.0
33.0
36
10
30
19.0
21.0
25
10
30
18.0
20.0
24
12
Configuration
Isolated drain
Isolated drain
Common drain
Isolated drain
Isolated drain
Common drain
Max.
V
DS
(V)
PMN34UN
30
PMN27UN
20
PMN40LN
30
PMN55LN
20
PMN34LN
20
PMN28UN
12
PMN45EN
30
PMN23UN
20
Circuit Diagram
Typical R
DS(on)
mΩ
V
GS
=10 V V
GS
=4.5 V V
GS
=2.5 V V
GS
=1.8 V
-
38
45
54
-
27
32
39
32
40
-
-
55
70
-
-
28
34
-
-
-
28
32
39
32
42
-
-
-
23
28
36.4
V
GS
8
8
15
15
15
8
20
8
I
D
max.
4.9
5.7
5.4
4.1
5.7
5.7
5.2
6.4
V
DS
(V)
PH3830L
PH5330E
PH7030L
PH4530L
PH3120L
30
30
30
30
30
Max R
DS(on)
(mΩ)
V
GS
10 V
V
GS
4.5 V
3.8
4.9
5.7
8.5
7.9
10.0
6.3
9.0
2.4
3.4
Q
GD
(nC)
11.0
6.0
3.2
4.1
12.8
Q
Gtotal
(nC)
33.0
21.0
12.0
21.0
48.5
Circuit Diagram
Circuit Diagram
battery+
Circuit Diagram
Q1
Rsense
Circuit Diagram
+
Vin
V
CC
S1
M
C1
sense
battery
sense
V
CC
Q3
Rgate1
Vdr ive H S
gate 1
gate 2
PWM
CONTROLLER
C0
CONTROL IC
+
L1_1
V driveLS
V
o
Ga t e D rive I C
I SL620 5 or I SL6 207
CB oo t
Q1
PH 70 30L
battery
CONTROLLER
R1
Q1
V
G
NE57600
NE57605
NE57607
NE57608
Q4
D1
BA T 5 4
L0
V
G
+
L2_2
V
CC
Q5
+
bra530
Ci n
Ga t e
Dr iv e
IC
Vo ut
L1
Co ut
Rgate2
Q6
PW M
R2
bra203
battery−
Q2
0V
0V
0V
0V
bra531
Q2
48
49
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