WM8310GEB/V Wolfson Microelectronics, WM8310GEB/V Datasheet - Page 93

• Manufacturer Part Number: WM8310GEB/V
• Description: POWER MANAGEMENT SUBSYSTEM, 169BGA
• Manufacturer: Wolfson Microelectronics

Specifications of WM8310GEB/V

• Supply Voltage: 7V
• No. Of Step-down Dc - Dc Converters: 4
• No. Of Ldo Regulators: 11
• Digital Ic Case Style: BGA
• No. Of Pins: 169
• No. Of Regulated Outputs: 13
• Operating Temperature Range: -40°C To
• Rohs Compliant: Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Pre-Production
Forced Continuous Conduction
Mode (FCCM)
Continuous / Discontinuous
Conduction with Pulse-Skipping
Mode (CCM/DCM with PS)
Hysteretic Mode
LDO Mode
Table 46 Step-Down DC-DC Converter Operating Modes Summary
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MODE
LDO mode is suitable for light loads, and provides a ripple-free output. The LDO mode features a
very low start-up current; this mode can be used to avoid the higher in-rush current that occurs in the
switching converter modes. The efficiency is dependent on the input - output voltage configuration;
the LDO mode can be highly efficient, but may also be unacceptably inefficient. If an improvement in
power efficiency is required, then Hysteretic mode may be the preferred choice or, for better EMI and
voltage ripple, DCM with Pulse-Skipping may be the optimum selection.
Operating Mode Summary
Typical Connections
The typical connections to DC-DC Converter 1 are illustrated in Figure 20. The equivalent circuit
applies to DC-DC Converters 2 and 3 also.
The input voltage connection to DC-DC Converters 1, 2 and 3 is provided on DC1VDD, DC2VDD and
DC3VDD respectively; these are typically connected to the SYSVDD voltage node. Note that the
internal supply pins PVDD1 and PVDD2 should also be connected to SYSVDD.
Figure 20 Step-Down DC-DC Converter Connections
The recommended output capacitor C
that the DCm_CAP register field must be set according to the output capacitance on each DC-DC
Converter in order to achieve best performance.
In the case of DC-DC1 and DC-DC2, the recommended inductor component varies according to the
switching frequency.
Buck converter operation where inductor
current is continuous at all times.
Buck converter operation where inductor
current may be discontinuous under reduced
loads; pulse-skipping also enabled under
lighter loads.
The converter uses a hysteretic control
scheme with pulsed switching operation. The
control circuitry is disabled intermittently for
power saving.
No FET switching at all; linear regulator
operation.
DESCRIPTION
OUT
varies according to the required transient response. Note
High performance for all static and transient
load conditions. Fixed frequency switching
offers best compatibility with sensitive
circuits.
High efficiency for all static and transient
load conditions. Performance may be less
than FCCM mode for heavy load transients.
High efficiency for light static and light
transient loads only. Maximum load current
is restricted; output voltage ripple is
increased.
Power saving mode for light loads only. High
efficiency for ultra light loads. Low current
soft-start control.
APPLICATION
PP, December 2009, Rev 3.0
WM8310
93