NS7520B-1-C36 Digi International, NS7520B-1-C36 Datasheet - Page 31

• Manufacturer Part Number: NS7520B-1-C36
• Description: IC ARM MICROPROCESSOR 177BGA
• Manufacturer: Digi International
• Series: NET+ARM®r

Specifications of NS7520B-1-C36

• Applications: Network Processor
• Core Processor: ARM7
• Program Memory Type: External Program Memory
• Controller Series: -
• Ram Size: External
• Interface: EBI/EMI, Ethernet, DMA, SPI, UART
• Number Of I /o: 16
• Voltage - Supply: 1.4 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 177-LFBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Table 8: Output buffer derating by load capacitance
Figure 8 illustrates the recommended oscillator circuit details.
Figure 8: Oscillator circuit details
Oscillator Characteristics
CS[4:0]_, CAS[3:0], RW_, WE_, OE_
MDC, TXD[3:0], TXER, TXEN, TDO
Signal
Rise time = 18ns;
0.8V to 2.0V
3R3V
RESET_
Rise/fall time. The max rise/fall time on the system clock input pin is 1.5ns when used
with an external oscillator.
Duty cycle. The duty cycle is system-dependent with an external oscillator. It affects the
setup and hold times of signals that change in the falling clock edges, such as WE_/OE_.
Recommendation: Use a 3.3V, 50±10% duty cycle oscillator with a 100 ohm series resistor
at the output. The PLLs can handle a 25% duty cycle clock (minimum high/low time
4.5nS).
TB1
100nF
Optional 36.864-55.296MHz Oscillator
PLL bypassed - U1 & R2 OUT, R1 IN
C3
A 18.432MHz crystal or 55.296MHz
oscillator allows full speed operation.
PLL enabled - U1 & R2 IN, R1 OUT
4
2
1
C1
10pF
C2
10pF
1
2
Y2
SM_Oscillator
VCC
GND
TEST
U1
NC
LVC04
10-20MHz
OUT
X2
3
5
4
3
3R3V
R3
1M
R2
0 OHM
100 OHM
0 OHM
R4
R11
XTAL1
XTAL2
R1
10K
K14
K12
L13
A10
0.137
0.274
Derating (ns/pF)
w w w . d i g i . c o m
SCANEN_
RESET_
XTAL1
XTAL2
NS7520
O s c i l l a t o r C h a r a c t e r i s t i c s
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