Datasheet

LPC1311_13_42_43 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 5 — 6 June 2012 52 of 74
NXP Semiconductors
LPC1311/13/42/43
32-bit ARM Cortex-M3 microcontroller
10.4 Internal oscillators
[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.
[1] Typical ratings are not guaranteed. The values listed are at nominal supply voltages.
[2] The typical frequency spread over processing and temperature (T
amb
= −40 °C to +85 °C) is ±40 %.
[3] See the LPC13xx user manual.
Table 15. Dynamic characteristics: IRC
T
amb
= −40 °C to +85 °C; 2.7 V ≤ V
DD
≤ 3.6 V
[1]
.
Symbol Parameter Conditions Min Typ
[2]
Max Unit
f
osc(RC)
internal RC oscillator frequency - 11.88 12 12.12 MHz
Conditions: Frequency values are typical values. 12 MHz ± 1 % accuracy is guaranteed for
2.7 V ≤ V
DD
≤ 3.6 V and T
amb
= −40 °C to +85 °C. Variations between parts may cause the IRC to
fall outside the 12 MHz ± 1 % accuracy specification for voltages below 2.7 V.
Fig 27. Internal RC oscillator frequency f versus temperature
temperature (°C)
−40 853510 60−15
002aae987
11.95
12.05
12.15
f
(MHz)
11.85
V
DD
= 3.6 V
3.3 V
3.0 V
2.7 V
2.4 V
2.0 V
Table 16. Dynamic characteristics: Watchdog oscillator
Symbol Parameter Conditions Min Typ
[1]
Max Unit
f
osc(int)
internal oscillator frequency DIVSEL = 0x1F, FREQSEL = 0x1 in the
WDTOSCCTRL register;
[2][3]
-7.8 - kHz
DIVSEL = 0x00, FREQSEL = 0xF in the
WDTOSCCTRL register
[2][3]
- 1700 - kHz