Datasheet
LPC185X_3X_2X_1X All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 4.1 — 6 May 2014 106 of 148
NXP Semiconductors
LPC185x/3x/2x/1x
32-bit ARM Cortex-M3 microcontroller
11.4 Crystal oscillator
[1] Parameters are valid over operating temperature range unless otherwise specified.
[2] Typical ratings are not guaranteed. The values listed are at room temperature (25 C), nominal supply
voltages.
[3] Indicates RMS period jitter.
[4] PLL-induced jitter is not included.
[5] Select HF = 0 in the XTAL_OSC_CTRL register.
[6] Select HF = 1 in the XTAL_OSC_CTRL register.
11.5 IRC oscillator
[1] Typical ratings are not guaranteed. The values listed are at room temperature (25 C), nominal supply
voltages.
11.6 RTC oscillator
See Section 13.3 for connecting the RTC oscillator to an external clock source.
[1] Parameters are valid over operating temperature range unless otherwise specified.
[2] Typical ratings are not guaranteed. The values listed are at room temperature (25 C), nominal supply
voltages.
Table 18. Dynamic characteristic: oscillator
T
amb
=
40
C to +105
C; V
DD(IO)
over specified ranges; 2.2 V
V
DD(REG)(3V3)
3.6 V.
[1]
Symbol Parameter Conditions Min Typ
[2]
Max Unit
Low-frequency mode (1-20 MHz)
[5]
t
jit(per)
period jitter time 5 MHz crystal
[3][4]
-13.2- ps
10 MHz crystal - 6.6 - ps
15 MHz crystal - 4.8 - ps
High-frequency mode (20 - 25 MHz)
[6]
t
jit(per)
period jitter time 20 MHz crystal
[3][4]
-4.3- ps
25 MHz crystal - 3.7 - ps
Table 19. Dynamic characteristic: IRC oscillator
2.2 V
V
DD(REG)(3V3)
3.6 V
Symbol Parameter Conditions Min Typ
[1]
Max Unit
f
osc(RC)
internal RC
oscillator
frequency
-40 C T
amb
0 C 12.0 - 3 % 12.0 112.0 + 3 % MHz
0 C T
amb
85 C 12.0 - 1.5 % 12.0 12.0 + 1.5 % MHz
85 C T
amb
£ 105 C 12.0 - 3 % 12.0 12.0 + 3 % MHz
Table 20. Dynamic characteristic: RTC oscillator
T
amb
=
40
C to +105
C; 2.2 V
V
DD(REG)(3V3)
3.6 V or 2.2 V
V
BAT
3.6 V
[1]
Symbol Parameter Conditions Min Typ
[1]
Max Unit
f
i
input frequency - - 32.768 - kHz
I
CC(osc)
oscillator supply
current
280 800 nA