EM773FHN33 NXP Semiconductors, EM773FHN33 Datasheet - Page 41

• Manufacturer Part Number: EM773FHN33
• Description: The EM773 is an ARM Cortex-M0 based, low-cost 32-bit energy metering IC, designed for 8/16-bit smart metering applications
• Manufacturer: NXP Semiconductors

NXP Semiconductors
EM773
Product data sheet
11.2 XTAL Printed Circuit Board (PCB) layout guidelines
Table 15.
Table 16.
The crystal should be connected on the PCB as close as possible to the oscillator input
and output pins of the chip. Take care that the load capacitors C
of third overtone crystal usage have a common ground plane. The external components
must also be connected to the ground plain. Loops must be made as small as possible in
Fundamental oscillation
frequency F
5 MHz - 10 MHz
10 MHz - 15 MHz
15 MHz - 20 MHz
Fundamental oscillation
frequency F
15 MHz - 20 MHz
20 MHz - 25 MHz
1 MHz - 5 MHz
Fig 23. Oscillator modes and models: oscillation mode of operation and external crystal
model used for C
Recommended values for C
components parameters) low frequency mode
Recommended values for C
components parameters) high frequency mode
OSC
OSC
All information provided in this document is subject to legal disclaimers.
XTALIN
C X1
EM773
Rev. 2 — 3 January 2012
XTAL
X1
Crystal load
capacitance C
10 pF
20 pF
30 pF
10 pF
20 pF
30 pF
10 pF
20 pF
10 pF
Crystal load
capacitance C
10 pF
20 pF
10 pF
20 pF
/C
X2
XTALOUT
evaluation
C X2
X1
X1
/C
/C
L
L
X2
X2
in oscillation mode (crystal and external
in oscillation mode (crystal and external
Maximum crystal
series resistance R
< 300 
< 300 
< 300 
< 300 
< 200 
< 100 
< 160 
< 60 
< 80 
Maximum crystal
series resistance R
< 180 
< 100 
< 160 
< 80 
=
S
S
X1
L
C L
R S
, C
002aag731
External load
capacitors C
18 pF, 18 pF
39 pF, 39 pF
57 pF, 57 pF
18 pF, 18 pF
39 pF, 39 pF
57 pF, 57 pF
18 pF, 18 pF
39 pF, 39 pF
18 pF, 18 pF
External load
capacitors C
18 pF, 18 pF
39 pF, 39 pF
18 pF, 18 pF
39 pF, 39 pF
Energy metering IC
X2
© NXP B.V. 2012. All rights reserved.
, and C
C P
EM773
X3
X1
X1
in case
, C
, C
41 of 51
X2
X2