LC87F1D64A Datasheet, PDF (13/29 Pages) Sanyo Semicon Device – CMOS IC FROM 64K byte, RAM 4K byte on-chip 8-bit 1-chip Microcontroller with Full-Speed USB

LC87F1D64A
USB Reference Power Option
When a voltage 4.5 to 5.5V is supplied to VDD1 and the internal USB reference voltage circuit is activated, the
reference voltage for USB port output is generated. The active/inactive state of reference voltage circuit can be
switched by the option select. The procedure for marking the option selection is described below.
(1)
(2)
(3)
(4)
Option select
USB Regulator
USE
USE
USE
NONUSE
USB Regulator at HOLD mode
USE
NONUSE
NONUSE
NONUSE
USB Regulator at HALT mode
USE
NONUSE
USE
NONUSE
Reference voltage circuit
state
Normal state
HOLD mode
active
active
active
inactive
active
inactive
inactive
inactive
HALT mode
active
inactive
active
inactive
• When the USB reference voltage circuit is made inactive, the level of the reference voltage for USB port output is
equal to VDD1.
• Selection (2) or (3) can be used to set the reference voltage circuit inactive in HOLD or HALT mode.
• When the reference voltage circuit is activated, the current drain increase by approximately 100μA compared with
when the reference voltage circuit is inactive.
Example 1: VDD1=VDD2=3.3V
• Inactivating the reference voltage circuit (selection (4)).
• Connecting VDD3 to VDD1 and VDD2.
LSI
P70/P27
Power supply
3.3V
VDD1
VDD2
1.5kΩ
D+
27 to 33Ω ^{To USB connector}
D-
2.2μF ^*1
*1: It is necessary to adjust
the value with the IC
mounted on the board.
VDD3
5pF
UFILT
VSS1 VSS2 VSS3
0Ω
2.2μF
Example 2: VDD1=VDD2=5.0V
• Activating the reference voltage circuit (selection (1)).
• Isolating VDD3 from VDD1 and VDD2, and connecting capacitor between VDD3 and VSS.
Power supply
5V
2.2μF
LSI
P70/P27
VDD1
D+
D-
VDD2
VDD3 ^UFILT
0.1µF
VSS1 VSS2 VSS3
1.5kΩ
27 to 33Ω
To USB connector
5pF
0Ω
2.2μF
No.A1220-13/29