μ
PD720210
7. Peripheral Component Connection
R19UH0093EJ0200 Rev.2.00
Page 56 of 59
May 26, 2014
7.10 Internal Switching Regulator (5 V
1.05 V) Connection (in use)
Figure 7-10. Internal Switching Regulator Connection in use
It is necessary to use the correct Field Effect Transistor (FET) for the part of this switching regulator.
The requirements for this FET are as follows.
1) Pch Vt: <2.5V
2) P-ch gate capacitance (Ciss): <270pF
3) Switching Period (On Time: Td+Tr, OffTime: Td+Tf) Nch<30ns, Pch<65ns
4) P-N One package, Single Die
5) Maximum Power Dissipation (Pd): >1.5W
6) Drain Current (Id): Continuous >1.5A
7) On Resistance (Rds): <170mOHM (Vgs=4.5V)
Remark:
Recommended part for FET is QS6M3 (ROHM). Renesas is unaware of any other acceptable
alternative device to the identified FET.
Important:
Please note that there is no known acceptable alternate device for the ROHM QS6M3 transistor noted in the
μ
PD720210 User’s Manual, as shown in the excerpt above. The reason is that this transistor carries the main
load current for the 1.05V power used by the
μ
PD720210 and may become excessively hot if an alternate
transistor type is used. The heating can be severe enough to cause discoloration of the circuit board and
possible damage to the end product and property
unless the specified transistor is used as shown.
The only alternative is to use an external 1.05V switching regulator instead of the on-chip regulator, as shown
in the
μ
PD720210 User’s Manual, Section 7.11.
"Notwithstanding anything to the contrary, Renesas shall not be responsible for any loss or
damage resulting
from Customer's use or incorporation of any components, including any
FET, used in the Customer's design,
system or end product. Customer is solely responsible
for any and all decisions concerning its design, the
components used therein, its assembly
and functionality."
PGDRV
μ
PD720210
QS6M3
NGDRV
ILIM
V10FB
56Ω
470 KΩ
68Ω
5V
4.7uF
1.05V
4.7uH
22uF
3
1
6
2
4
5
ROHM
Summary of Contents for Renesas mPD720210
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