CC2538 Datasheet, PDF (15/24 Pages) TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS – A Powerful System-On-Chip for 2.4-GHz IEEE 802.15.4, 6LoWPAN and ZigBee Applications

CC2538
www.ti.com
SWRS096A – DECEMBER 2012 – REVISED APRIL 2013
APPLICATION INFORMATION
Few external components are required for the operation of the CC2538xFnn. Figure 2 is a typical application
circuit. For a complete USB reference design, see the CC2538xFnn product page on www.ti.com. Table 2 lists
typical values and descriptions of external components. The USB_P and USB_N pins require series resistors
R21 and R31 for impedance matching, and the D+ line must have a pullup resistor, R32. The series resistors
should match the 90-Ω ±15% characteristic impedance of the USB bus. Notice that the pullup resistor and
DVDD_USB require connection to a voltage source between 3 V and 3.6 V (typically 3.3 V). To accomplish this,
it is recommend to connect the D+ pull-up to a port/pin that does not have an internal pull-up (that is, PC0..3),
instead of connecting it directly to a 3.3V supply (that is, software control of D+ pull-up recommended).
2.0V-3.6V power supply
3.3V power supply
C561
Optional 32kHz crystal
C451
R31
D+
D-
R21
R32
C31 C21
C441
1 DGND_USB
2 USB_P
3 USB_N
4 DVDD_USB
5 PB0
6 PC7
7 PC6
8 PC5
9 PC4
10 VDD
11 PC3
12 PC2
13 PC1
14 PC0
CC2538
DIE ATTACH PAD:
Power supply decoupling capacitors are not shown
Digital I/O not connected
R_BIAS 42
AVDD 41
AVDD 40
AVDD 39
RF_N 38
RF_P 37
AVDD 36
XOSC32M_Q2 35
XOSC32M_Q1 34
AVDD 33
DCOUPL2 32
PD5 31
PD4 30
PD3 29
C281
R421
C382
C381
L381
C371
C372
L372
C321
C341
XTAL
C351
R281
RESET_N
Figure 2. CC2538xFnn Application Circuit
Antenna
(50 Ohm)
L373
2 nH
L374
3.3 nH
C373
1.2 pF
Copyright © 2012–2013, Texas Instruments Incorporated
Product Folder Links: CC2538
Submit Documentation Feedback
15